Sample records for arcs atomic-scale dynamics

  1. atomic-scale dynamics 96-erd-046: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    atomic-scale dynamics 96-erd-046 First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Atomic-scale processes...

  2. Atomic-scale investigations of the struct. and dynamics of complex catalytic materials

    SciTech Connect (OSTI)

    Karl Sohlberg, Drexel University

    2007-05-16T23:59:59.000Z

    By some accounts, catalysis impacts ? 30% of GDP in developed countries [Maxwell, I. E. Nature 394, 325-326 (1998)]. Catalysis is the enabling technology for petroleum production, for control of gaseous emissions from petroleum combustion, and for the production of industrial and consumer chemicals. Future applications of catalysis are potentially even more far reaching. There is an ever-growing need to move the economy from a fossil-fuel energy base to cleaner alternatives. Hydrogen-based combustion systems and fuel cells could play a dominant role, given a plentiful and inexpensive source of hydrogen. Photocatalysis is the most promising clean technology for hydrogen production, relying solely on water and sunlight, but performance enhancements in photocatalysis are needed to make this technology economically competitive. Given the enormously wide spread utilization of catalysts, even incremental performance enhancements would have far-reaching benefits for multiple end-use sectors. In the area of fuel and chemical production, such improvements would translate into vast reductions in energy consumption. At the consumption end, improvements in the catalysts involved would yield tremendous reductions in pollution. In the area of photocatalysis, such efficiency improvements could finally render hydrogen an economically viable fuel. Prerequisite to the non-empirical design and refinement of improved catalysts is the identification of the atomic-scale structure and properties of the catalytically active sites. This has become a major industrial research priority. The focus of this research program was to combine atomic-resolution Z-contrast electron microscopy with first-principles density functional theory calculations to deliver an atomic-scale description of heterogeneous catalytic systems that could form the basis for non-empirical design of improved catalysts with greater energy efficiency.

  3. atomic-scale dynamical structures: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    presentee et method . . . . . . . . . . . . . . . . . . . . . 10 1.2 Dynamic SSI problem in earthquake engineering, Structures et Materiaux - CNRS U.M.R. 8579...

  4. A Dynamic Traveling Salesman Problem with Stochastic Arc Costs

    E-Print Network [OSTI]

    Alejandro Toriello

    2012-08-31T23:59:59.000Z

    Aug 31, 2012 ... Abstract: We propose a dynamic traveling salesman problem (TSP) with stochastic arc costs motivated by applications, such as dynamic ...

  5. Dynamic Resource Allocation with the arcControlTower

    E-Print Network [OSTI]

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01T23:59:59.000Z

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job management system (PanDA) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experienc...

  6. CHEP2015: Dynamic Resource Allocation with arcControlTower

    E-Print Network [OSTI]

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01T23:59:59.000Z

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job mangement system (Panda) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experience...

  7. Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.

    SciTech Connect (OSTI)

    Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

    2011-06-01T23:59:59.000Z

    Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

  8. Computational study of flow dynamics from a dc arc plasma jet

    E-Print Network [OSTI]

    Juan Pablo Trelles

    2013-03-15T23:59:59.000Z

    Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviations between heavy-species and electron temperatures in the plasma fringes, the development of shear flow instabilities around the jet, the occurrence of localized regions with high electric fields far from the arc, and the formation and evolution of coherent flow structures.

  9. Dynamic Graphics in a GIS: A Link between ARC INFOTM and XGobi

    E-Print Network [OSTI]

    Symanzik, Jürgen

    Dynamic Graphics in a GIS: A Link between ARC INFOTM and XGobi Jurgen Symanzik1, James Majure2 graphics program, XGobi. GISs provide a user with a standard and convenient software for spatial graphics program for data visualization in the X Window SystemTM . It is designed for the exploration

  10. Tomographic study of atomic-scale redistribution of platinum...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    atomic-scale redistribution of platinum during the silicidation of Ni0.95Pt0.05Si(100) thin films Home Author: P. Adusumilli, L. J. Lauhon, D. N. Seidman, C. E. Murray, O....

  11. Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint

    SciTech Connect (OSTI)

    Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

    2011-07-01T23:59:59.000Z

    Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve full atomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface is maximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.

  12. The dynamics of droplet formation and detachment in gas metal arc welding

    SciTech Connect (OSTI)

    Johnson, J.A.; Smartt, H.B.; Clark, D.E.; Carlson, N.M.; Watkins, A.D.; Lethcoe, B.J.

    1990-01-01T23:59:59.000Z

    Experimental measurements of gas metal arc welding are required for the development and confirmation of models of the process. This paper reports on two experiments that provide information for models of the arc physics and of the weld pool dynamics. The heat transfer efficiency of the spray transfer mode in gas metal arc welding was measured using a calorimetry technique. The efficiency varied from 75 to 85%. A special fixture was used to measure the droplet contribution, which is determined to be between 35 and 45% of the total input energy. A series of experiments was performed at a variety of conditions ranging from globular to spray to streaming transfer. The transfer was observed by taking high-speed movies at 500 to 5000 frames per second of the backlighted droplets. An automatic image analysis system was used to obtain information about the droplets including time between detachments, droplet size, and droplet acceleration. At the boundary between the globular and spray modes, the droplet size varies between small droplets that melt off faster than average, resulting in a smaller electrode extension, and large droplets that melt off slower than average, resulting in an increase in the electrode extension. 5 refs., 4 figs., 2 tabs.

  13. Atomic scale mixing for inertial confinement fusion associated hydro instabilities

    E-Print Network [OSTI]

    New York at Stoney Brook, State University of

    Atomic scale mixing for inertial confinement fusion associated hydro instabilities J. Melvina, , P Alamos, NM 87545, USA Abstract Hydro instabilities have been identified as a potential cause- able. We find numerical convergence for this important quantity, in a purely hydro study, with only

  14. Modeling Arcs

    SciTech Connect (OSTI)

    Insepov, Z.; Norem, J. [Argonne National Lab, Argonne, IL 60439 (United States); Vetizer, S.; Mahalingam, S. [Tech-X Corp., Boulder, CO (United States)

    2011-12-23T23:59:59.000Z

    Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gradient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.

  15. High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    DOE Patents [OSTI]

    Shimer, D.W.; Lange, A.C.

    1995-05-23T23:59:59.000Z

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

  16. High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    DOE Patents [OSTI]

    Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

  17. Atomic-scale electron-beam sculpting of defect-free graphene nanostructures

    E-Print Network [OSTI]

    Dekker, Cees

    Atomic-scale electron-beam sculpting of defect-free graphene nanostructures Bo Song, Grégory F.w.zandbergen@tudelft.nl ABSTRACT. In order to harvest the many promising properties of graphene in (electronic) applications a temperature-dependent self-repair mechanism allowing damage-free atomic-scale sculpting of graphene using

  18. Atomic-scale studies on the growth of palladium and titanium on GaN(0001)

    E-Print Network [OSTI]

    Castell, Martin

    Atomic-scale studies on the growth of palladium and titanium on GaN(0001) C. No¨renberg a,b,*, M nitride; Palladium; Titanium; Alloys; Epitaxy; Metal­semiconductor interfaces; Nanostructures; Scanning;Here, we have focused on atomic-scale studies of the ini- tial growth stages of palladium and titanium

  19. Bending buckling of single-walled carbon nanotubes by atomic-scale finite element

    E-Print Network [OSTI]

    Jiang, Hanqing

    - vered SWNT loaded by a follower lateral force at the free end and found that it exhibited local bucklingBending buckling of single-walled carbon nanotubes by atomic-scale finite element X. Guo a , A Abstract This paper employs the atomic-scale finite element method to study bending buckling of single

  20. Investigation of stabilization/solidification for treatment of electric arc furnace dust: Dynamic leaching of monolithic specimens

    SciTech Connect (OSTI)

    Laforest, Guylaine [Centre de Recherche sur les Infrastructures en Beton, Departement de Geologie et de Genie Geologique, Universite Laval, Quebec, Qc, G1K 7P4 (Canada)], E-mail: guylaine.laforest.1@ulaval.ca; Duchesne, Josee [Centre de Recherche sur les Infrastructures en Beton, Departement de Geologie et de Genie Geologique, Universite Laval, Quebec, Qc, G1K 7P4 (Canada)

    2007-12-15T23:59:59.000Z

    Diffusion-controlled leaching of heavy metals (Cr, Ni, Pb and Zn) from electric arc furnace dust treated with ground granulated blast furnace slag (GGBFS) and with ordinary Portland cement (OPC) was evaluated. Monolithic specimens were evaluated under dynamic leaching conditions for 84 days with periodic leachant renewal. The influence of leaching time, nature of the leachant, binder type and the water/solid ratio of the monoliths were investigated. Results obtained showed both binders can immobilize heavy metals in the monoliths under dynamic leaching conditions, with cumulative quantity of leached metal under 0.138 mg (Cr). Alkaline leachant increased metal release from specimens and reducing the water/solid ratio of the monolith allowed for a decrease in the cumulative mass of metals leached. Chemical and mineralogical characterizations indicated that the metals were evenly distributed throughout the specimens for both binders. Decalcification was observed on the OPC monolith border following leaching. This decrease in Ca corresponded to an altered zone (20 {mu}m), identified by scanning electron microscopy. The GGBFS sample did not show an altered zone.

  1. Implementation and evaluation of modified dynamic conformal arc (MDCA) technique for lung SBRT patients following RTOG protocols

    SciTech Connect (OSTI)

    Shi, Chengyu, E-mail: shicy1974@gmail.com [St. Vincent's Medical Center, Bridgeport, CT (United States); Tazi, Adam; Fang, Deborah Xiangdong; Iannuzzi, Christopher [St. Vincent's Medical Center, Bridgeport, CT (United States)

    2013-10-01T23:59:59.000Z

    To implement modified dynamic conformal arc (MDCA) technique and Radiation Therapy Oncology Group (RTOG) protocols in our clinic for stereotactic body radiation therapy (SBRT) treatment of patients with Stage I/II non–small cell lung cancer. Five patients with non–small cell lung cancer have been treated with SBRT. All the patients were immobilized using CIVCO Body Pro-Lok system and scanned using GE 4-slice computed tomography. The MDCA technique that was previously published was adopted as our planning technique, and RTOG protocols for the lung SBRT were followed. The patients were treated on Novalis Tx system with cone-beam computed tomography imaging guidance. All the patient plans passed the RTOG criteria. The conformal index ranges from 0.99 to 1.12 for the planning target volume, and the biological equivalent dose for the planning target volume is overall 100 Gy. Critical structures (lung, spinal cord, brachial plexus, skin, and chest wall) also meet RTOG protocols or published data. A 6-month follow-up of one of the patients shows good local disease control. We have successfully implemented the MDCA technique into our clinic for the lung SBRT program. It shows that the MDCA is useful and efficient for the lung SBRT planning, with the plan quality meeting the RTOG protocols.

  2. Adhesion, Lubrication, and Wear on the Atomic Scale James B. Adams

    E-Print Network [OSTI]

    Adams, James B

    , lubrication and wear) of tribology on the atomic Scale with a focus on our group's work on Aluminum. Adhesion are processes that affect many industries, including metal forming, aerospace, automotive, and microelectronics. Adhesion is critical to the success of many applications, from automotive tires (the infamous Firestone

  3. Three-dimensional modeling of the plasma arc in arc welding

    SciTech Connect (OSTI)

    Xu, G.; Tsai, H. L. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 1870 Miner Circle, Rolla, Missouri 65409 (United States); Hu, J. [Department of Mechanical Engineering, University of Bridgeport, Bridgeport, Connecticut 06604 (United States)

    2008-11-15T23:59:59.000Z

    Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such as an external magnetic field. It also provides more accurate boundary conditions when modeling the weld pool dynamics. The present work lays a foundation for true three-dimensional comprehensive modeling of GTAW and GMAW including the plasma arc, weld pool, and/or electrode.

  4. Atomic Scale Picture of the Ion Conduction Mechanism in Tetrahedral Network of Lanthanum Barium Gallate

    SciTech Connect (OSTI)

    Jalarvo, Niina H [ORNL] [ORNL; Gourdon, Olivier [ORNL] [ORNL; Bi, Zhonghe [ORNL] [ORNL; Gout, Delphine J [ORNL] [ORNL; Ohl, Michael E [ORNL] [ORNL; Paranthaman, Mariappan Parans [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    Combined experimental study of impedance spectroscopy, neutron powder diffraction and quasielastic neutron scattering was performed to shed light into the atomic scale ion migration processes in proton and oxide ion conductor; La0.8Ba1.2GaO3.9 . This material consist of tetrahedral GaO4 units, which are rather flexible and rocking motion of these units promotes the ionic migration process. The oxide ion (vacancy) conduction takes place on channels along c axis, involving a single elementary step, which occurs between adjacent tetrahedron (inter-tetrahedron jump). The proton conduction mechanism consists of intra-tetrahedron and inter-tetrahedron elementary processes. The intra-tetrahedron proton transport is the rate-limiting process, with activation energy of 0.44 eV. The rocking motion of the GaO4 tetrahedron aids the inter-tetrahedral proton transport, which has the activation energy of 0.068 eV.

  5. Atomic Scale Design and Three-Dimensional Simulation of Ionic Diffusive Nanofluidic Channels

    E-Print Network [OSTI]

    Park, Jin Kyoung; We, Guo-Wei

    2015-01-01T23:59:59.000Z

    Recent advance in nanotechnology has led to rapid advances in nanofluidics, which has been established as a reliable means for a wide variety of applications, including molecular separation, detection, crystallization and biosynthesis. Although atomic and molecular level consideration is a key ingredient in experimental design and fabrication of nanfluidic systems, atomic and molecular modeling of nanofluidics is rare and most simulations at nanoscale are restricted to one- or two-dimensions in the literature, to our best knowledge. The present work introduces atomic scale design and three-dimensional (3D) simulation of ionic diffusive nanofluidic systems. We propose a variational multiscale framework to represent the nanochannel in discrete atomic and/or molecular detail while describe the ionic solution by continuum. Apart from the major electrostatic and entropic effects, the non-electrostatic interactions between the channel and solution, and among solvent molecules are accounted in our modeling. We deriv...

  6. An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes

    E-Print Network [OSTI]

    Grujicic, Mica

    Growth of carbon nanotubes during transition-metal particles catalytically-assisted thermal decomposition of the transition-metal particles and onto the surface of carbon nanotubes, carbon atom attachment to the growing. Carbon nanotubes are generally processed by laser ablation of carbon rods e.g. [7], a direct current arc

  7. www.sbc.anl.gov The Structural Biology Center enables the atomic-scale study of macromolecular

    E-Print Network [OSTI]

    Kemner, Ken

    systems using very small crystal samples. It also offers the most efficient data collection and structure to synchrotron data collection W H O W E A R E Supported by the U.S. Department of Energy, the Structural Biologywww.sbc.anl.gov The Structural Biology Center enables the atomic-scale study of macromolecular

  8. Observation of atomic scale compositional and displacive modulations in incommensurate melilite electrolytes

    SciTech Connect (OSTI)

    Wei, Fengxia [Division of Materials Science and Engineering, Nanyang Technological University (Singapore); Williams, Tim [Monash Centre for Electron Microscopy, Monash University, Melbourne (Australia); An, Tao; Baikie, Tom; Kloc, Christian [Division of Materials Science and Engineering, Nanyang Technological University (Singapore); Wei, Jun [Singapore Institute of Manufacturing Technology, Agency for Science Technology and Research (Singapore); White, Tim, E-mail: tjwhite@ntu.edu.sg [Division of Materials Science and Engineering, Nanyang Technological University (Singapore)

    2013-07-15T23:59:59.000Z

    The paradigm that functional materials are adequately described as three-dimensional crystal structures is not universally tenable. Gallate melilites are efficient oxide ion conductors at intermediate temperatures (?750 °C) with non-rational crystallographic modulations presumed to play a key role in significantly enhancing oxygen mobility. Lattice distortions associated with incommensuration are usually extrapolated from diffraction analysis of volumes greatly exceeding the scale of modulation. Therefore, opportunities for making direct nanometric measurements are exceptionally valuable for correlating structure with function. In [CaLn]{sub 2}[Ga]{sub 2}[Ga{sub 2}O{sub 7}]{sub 2} (Ln=Nd, La) melilites, atomic displacive and compositional modulation waves can be imaged by high angle annular dark field and bright field scanning transmission electron microscopy with contrast quantified through electron scattering simulation. Here, we present atomic scale observations of (3+2)-dimensional modulations in gallate melilites which expands our understanding of the ion conduction mechanism and provides guidance for enhancing the performance of solid oxide fuel cells through crystal chemical tailoring. - Highlights: • Characterise the (3+2)-dimensional melilite electrolytes using STEM technique. • Direct observation on displacive and compositional modulation in melilites. • Structural flexibility reduces when increasing interstitial oxygen. • Domain-like incommensurate modulation model is proposed.

  9. Atomic Scale Design and Three-Dimensional Simulation of Ionic Diffusive Nanofluidic Channels

    E-Print Network [OSTI]

    Jin Kyoung Park; Kelin Xia; Guo-Wei We

    2015-03-02T23:59:59.000Z

    Recent advance in nanotechnology has led to rapid advances in nanofluidics, which has been established as a reliable means for a wide variety of applications, including molecular separation, detection, crystallization and biosynthesis. Although atomic and molecular level consideration is a key ingredient in experimental design and fabrication of nanfluidic systems, atomic and molecular modeling of nanofluidics is rare and most simulations at nanoscale are restricted to one- or two-dimensions in the literature, to our best knowledge. The present work introduces atomic scale design and three-dimensional (3D) simulation of ionic diffusive nanofluidic systems. We propose a variational multiscale framework to represent the nanochannel in discrete atomic and/or molecular detail while describe the ionic solution by continuum. Apart from the major electrostatic and entropic effects, the non-electrostatic interactions between the channel and solution, and among solvent molecules are accounted in our modeling. We derive generalized Poisson-Nernst-Planck (PNP) equations for nanofluidic systems. Mathematical algorithms, such as Dirichlet to Neumann mapping and the matched interface and boundary (MIB) methods are developed to rigorously solve the aforementioned equations to the second-order accuracy in 3D realistic settings. Three ionic diffusive nanofluidic systems, including a negatively charged nanochannel, a bipolar nanochannel and a double-well nanochannel are designed to investigate the impact of atomic charges to channel current, density distribution and electrostatic potential. Numerical findings, such as gating, ion depletion and inversion, are in good agreements with those from experimental measurements and numerical simulations in the literature.

  10. Rotating arc spark plug

    DOE Patents [OSTI]

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27T23:59:59.000Z

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  11. DC arc weld starter

    DOE Patents [OSTI]

    Campiotti, Richard H. (Tracy, CA); Hopwood, James E. (Oakley, CA)

    1990-01-01T23:59:59.000Z

    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  12. Atomic-scale observation of parallel development of super elasticity and reversible plasticity in GaAs nanowires

    SciTech Connect (OSTI)

    Bao, Peite; Du, Sichao; Zheng, Rongkun, E-mail: rongkun.zheng@sydney.edu.au [School of Physics, The University of Sydney, Sydney, NSW 2006 (Australia); Wang, Yanbo; Liao, Xiaozhou, E-mail: xiaozhou.liao@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Cui, Xiangyuan; Yen, Hung-Wei; Kong Yeoh, Wai; Ringer, Simon P. [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Gao, Qiang; Hoe Tan, H.; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Liu, Hongwei [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Zou, Jin [Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, QLD 4072 (Australia)

    2014-01-13T23:59:59.000Z

    We report the atomic-scale observation of parallel development of super elasticity and reversible dislocation-based plasticity from an early stage of bending deformation until fracture in GaAs nanowires. While this phenomenon is in sharp contrast to the textbook knowledge, it is expected to occur widely in nanostructures. This work indicates that the super recoverable deformation in nanomaterials is not simple elastic or reversible plastic deformation in nature, but the coupling of both.

  13. Energy-loss- and thickness-dependent contrast in atomic-scale electron energy-loss spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tan, Haiyan [Universit_e de Toulouse, Toulouse, France (Europe); National Institute of Standards Technology, Gaithersburg, MD (United States); Xin, Huolin L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhu, Ye [Monash Univ., Melbourne, VIC (Australia); Dwyer, Christian [Peter Grunberg Institute, Julich, Germany (Europe)

    2014-12-01T23:59:59.000Z

    Atomic-scale elemental maps of materials acquired by core-loss inelastic electron scattering often exhibit an undesirable sensitivity to the unavoidable elastic scattering, making the maps counter-intuitive to interpret. Here, we present a systematic study that scrutinizes the energy-loss and sample-thickness dependence of atomic-scale elemental maps acquired using 100 keV incident electrons in a scanning transmission electron microscope. For single-crystal silicon, the balance between elastic and inelastic scattering means that maps generated from the near-threshold Si-L signal (energy loss of 99 eV) show no discernible contrast for a thickness of 0.5? (? is the electron mean-free path, here approximately 110 nm). At greater thicknesses we observe a counter-intuitive “negative” contrast. Only at much higher energy losses is an intuitive “positive” contrast gradually restored. Our quantitative analysis shows that the energy-loss at which a positive contrast is restored depends linearly on the sample thickness. This behavior is in very good agreement with our double-channeling inelastic scattering calculations. We test a recently-proposed experimental method to correct the core-loss inelastic scattering and restore an intuitive “positive” chemical contrast. The method is demonstrated to be reliable over a large range of energy losses and sample thicknesses. The corrected contrast for near-threshold maps is demonstrated to be (desirably) inversely proportional to sample thickness. Implications for the interpretation of atomic-scale elemental maps are discussed.

  14. Atomic-Scale Chemical Imaging and Quantification of Metallic Alloy Structures by Energy-Dispersive X-Ray Spectroscopy

    SciTech Connect (OSTI)

    Lu, Ping [Sandia National Laboratories; Zhou, Lin [Ames Laboratory; Kramer, Matthew J. [Ames Laboratory; Smith, David J. [Arizona State University

    2014-02-04T23:59:59.000Z

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L21 phase with Ni0.48Co0.52 at A-sites, Al at B?-sites and Fe0.20Ti0.80 at B??-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems.

  15. Rates of tectonic and magmatic processes in the North Cascades continental magmatic arc

    E-Print Network [OSTI]

    Matzel, Jennifer E. Piontek, 1973-

    2004-01-01T23:59:59.000Z

    Continental magmatic arcs are among the most dynamic. geologic systems, and documentation of the magmatic, thermal, and tectonic evolution of arcs is essential for understanding the processes of magma generation, ascent ...

  16. Arc initiation in cathodic arc plasma sources

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA)

    2002-01-01T23:59:59.000Z

    A "triggerless" arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation. A conductive surface layer, such as graphite or the material being deposited, is formed on the surface of the insulator which separates the cathode from the anode. The mechanism of plasma production (and arc initiation) is based on explosive destruction of the layer-cathode interface caused by joule heating. The current flow between the thin insulator coating and cathode occurs at only a few contact points so the current density is high.

  17. Comparative dosimetric study of three-dimensional conformal, dynamic conformal arc, and intensity-modulated radiotherapy for brain tumor treatment using Novalis system

    SciTech Connect (OSTI)

    Ding Meisong [Department of Radiation Oncology, University of Colorado Health Science Center, Aurora, CO (United States)]. E-mail: Meisong.Ding@uchsc.edu; Newman, Francis M.S. [Department of Radiation Oncology, University of Colorado Health Science Center, Aurora, CO (United States); Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado Health Science Center, Aurora, CO (United States); Stuhr, Kelly M.S. [Department of Radiation Oncology, University of Colorado Health Science Center, Aurora, CO (United States); Johnson, Tim K. [Department of Radiation Oncology, University of Colorado Health Science Center, Aurora, CO (United States); Gaspar, Laurie E. [Department of Radiation Oncology, University of Colorado Health Science Center, Aurora, CO (United States)

    2006-11-15T23:59:59.000Z

    Purpose: To investigate the dosimetric differences among three-dimensional conformal radiotherapy (3D-CRT), dynamic conformal arc therapy (DCAT), and intensity-modulated radiotherapy (IMRT) for brain tumor treatment. Methods and Materials: Fifteen patients treated with Novalis were selected. We performed 3D-CRT, DCAT, and IMRT plans for all patients. The margin for the planning target volume (PTV) was 1 mm, and the specific prescription dose was 90% for all plans. The target coverage at the prescription dose, conformity index (CI), and heterogeneity index were analyzed for all plans. Results: For small tumors (PTV {<=}2 cm{sup 3}), the three dosimetric parameters had approximate values for both 3D-CRT and DCAT plans. The CI for the IMRT plans was high. For medium tumors (PTV >2 to {<=}100 cm{sup 3}), the three plans were competitive with each other. The IMRT plans had a greater CI, better target coverage at the prescription dose, and a better heterogeneity index. For large tumors (PTV >100 cm{sup 3}), the IMRT plan had good target coverage at the prescription dose and heterogeneity index and approximate CI values as those in the 3D-CRT and DCAT plans. Conclusion: The results of our study have shown that DCAT is suitable for most cases in the treatment of brain tumors. For a small target, 3D-CRT is useful, and IMRT is not recommended. For larger tumors, IMRT is superior to 3D-CRT and very competitive in sparing critical structures, especially for big tumors.

  18. Plasticity of metallic nanostructures : molecular dynamics simulations 

    E-Print Network [OSTI]

    Healy, Con

    2014-11-27T23:59:59.000Z

    During high speed cutting processes, metals are subject to high strains and strain rates. The dynamic nature of the deformation during high speed cutting makes it difficult to detect atomic scale deformation mechanisms ...

  19. Arc Position Sensing Technology

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    arc remelting (VAR) furnaces for industries that use specialty metals such as nickel, titanium, and zirconium. The technology could be used to help produce materials with stronger...

  20. Energy-loss- and thickness-dependent contrast in atomic-scale electron energy-loss spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tan, Haiyan; Xin, Huolin L.; Zhu, Ye; Dwyer, Christian

    2014-12-01T23:59:59.000Z

    Atomic-scale elemental maps of materials acquired by core-loss inelastic electron scattering often exhibit an undesirable sensitivity to the unavoidable elastic scattering, making the maps counter-intuitive to interpret. Here, we present a systematic study that scrutinizes the energy-loss and sample-thickness dependence of atomic-scale elemental maps acquired using 100 keV incident electrons in a scanning transmission electron microscope. For single-crystal silicon, the balance between elastic and inelastic scattering means that maps generated from the near-threshold Si-L signal (energy loss of 99 eV) show no discernible contrast for a thickness of 0.5? (? is the electron mean-free path, here approximately 110 nm). Atmore »greater thicknesses we observe a counter-intuitive “negative” contrast. Only at much higher energy losses is an intuitive “positive” contrast gradually restored. Our quantitative analysis shows that the energy-loss at which a positive contrast is restored depends linearly on the sample thickness. This behavior is in very good agreement with our double-channeling inelastic scattering calculations. We test a recently-proposed experimental method to correct the core-loss inelastic scattering and restore an intuitive “positive” chemical contrast. The method is demonstrated to be reliable over a large range of energy losses and sample thicknesses. The corrected contrast for near-threshold maps is demonstrated to be (desirably) inversely proportional to sample thickness. Implications for the interpretation of atomic-scale elemental maps are discussed.« less

  1. A new Embedded Atom Method potential for atomic-scale modeling of metal-silicon systems

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    those predicted with electronic structure calculations [5]. A comprehensive comparative study of the 2 calculations. First molecular dynamics simulations performed with the new potential for a Au monolayer island-Au structures are related to LDA calculations and earlier MEAM simulations. The EAM potential with explicit

  2. Welding arc initiator

    DOE Patents [OSTI]

    Correy, T.B.

    1989-05-09T23:59:59.000Z

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome. 3 figs.

  3. Welding arc initiator

    DOE Patents [OSTI]

    Correy, Thomas B. (Richland, WA)

    1989-01-01T23:59:59.000Z

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome.

  4. Proceedings of the 4th Symposium on AtomScale Surface and Interface Dynamics, March 23, 2000, Tsukuba, Japan

    E-Print Network [OSTI]

    , Tsukuba, Japan Ab inito thermodynamics and statistics of semiconductor growth, and self­functional theory based hybrid methods, which bridge the length and time scales from those of electron orbitals seconds. Thus, we are challenged by the need to bridge the length and the time scales by many orders

  5. Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling Microscopy and Spectroscopy

    E-Print Network [OSTI]

    Kim, Sehun

    Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling ReceiVed: June 26, 2010 Graphene was epitaxially grown on a 6H-SiC(0001) substrate by thermal the evolution of the graphene growth as a function of the temperature. We found that the evaporation of Si

  6. College of Design ARC Architecture

    E-Print Network [OSTI]

    MacAdam, Keith

    College of Design ARC Architecture KEY: # = new course * = course changed = course dropped,landscape,andarchitecturalspaceswithattentiontotheirapplicationtothearchitecturalexperience.Studio:4hoursperweek. Prereq: Admission to the School of Architecture. ARC 102 DRAWING II: OBSERVATIONAL OF ARCHITECTURE. (3

  7. Atomic scale studies of the chemistry of the Cu/MgO l brace 111 r brace heterophase interface

    SciTech Connect (OSTI)

    Jang, H.; Seidman, D.N. (Northwestern Univ., Evanston, IL (United States)); Merkle, K.L. (Argonne National Lab., IL (United States))

    1992-01-01T23:59:59.000Z

    The Cu/MgO (111) heterophase interface is studied using a combination of transmission electron microscopy, high resolution electron microscopy and atom-probe field-ion microscopy techniques. Wire and foil specimens of a Cu-2.8 at.% Mg alloy were internally oxidized to produce MgO precipitates at a number density of 5{center dot}10{sup 15}Cm{sup {minus}3} with a mean diameter of {approx}200 {Angstrom}. The MgO precipitates have a semicoherent interface with the Cu matrix and they exhibit a cube-on-cube orientation relationship. The octahedral-shaped MgO precipitates were analyzed using APFIM by dissecting along a <111> direction on an atomic scale. In this manner an MgO precipitate, with a (111) plane perpendicular to the axis of the APFIM, is uncovered after the Cu matrix has been mass analyzed. It was found that the terminating (222) plane of an MgO precipitate is pure oxygen, and the second (222) plane is pure Mg.

  8. Quantitative Z-Contrast Imaging of Supported Metal Complexes and Clusters - A Gateway to Understanding Catalysis on the Atomic Scale

    SciTech Connect (OSTI)

    Browning, Nigel D.; Aydin, C.; Lu, Jing; Kulkarni, Apoorva; Okamoto, Norihiko L.; Ortalan, V.; Reed, Bryan W.; Uzun, Alper; Gates, Bruce C.

    2013-09-01T23:59:59.000Z

    Z-contrast imaging in an aberration-corrected scanning transmission electron microscope can be used to observe and quantify the sizes, shapes, and compositions of the metal frames in supported mono-, bi-, and multimetallic metal clusters and can even detect the metal atoms in single-metal-atom complexes, as well as providing direct structural information characterizing the metal-support interface. Herein, we assess the major experimental challenges associated with obtaining atomic resolution Z-contrast images of the materials that are highly beam-sensitive, that is, the clusters readily migrate and sinter on support surfaces, and the support itself can drastically change in structure if the experiment is not properly controlled. Calibrated and quantified Z-contrast images are used in conjunction with exsitu analytical measurements and larger-scale characterization methods such as extended X-ray absorption fine structure spectroscopy to generate an atomic-scale understanding of supported catalysts and their function. Examples of the application of these methods include the characterization of a wide range of sizes and compositions of supported clusters, primarily those incorporating Ir, Os, and Au, on highly crystalline supports (zeolites and MgO).

  9. Automotive Research Center (ARC) "The Automotive Research Center (ARC) develops simulation and modeling tools for discovering

    E-Print Network [OSTI]

    Kamat, Vineet R.

    Automotive Research Center (ARC) "The Automotive Research Center (ARC) develops simulation with industry to leverage and transfer the efforts and results http://arc.engin.umich.edu/ #12;

  10. SU-E-J-70: Feasibility Study of Dynamic Arc and IMRT Treatment Plans Utilizing Vero Treatment Unit and IPlan Planning Computer for SRS/FSRT Brain Cancer Patients

    SciTech Connect (OSTI)

    Huh, S; Lee, S; Dagan, R; Malyapa, R; Mendenhall, N; Mendenhall, W; Ho, M; Hough, D; Yam, M; Li, Z [UFPTI, Jacksonville, FL (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To investigate the feasibility of utilizing Dynamic Arc (DA) and IMRT with 5mm MLC leaf of VERO treatment unit for SRS/FSRT brain cancer patients with non-invasive stereotactic treatments. The DA and IMRT plans using the VERO unit (BrainLab Inc, USA) are compared with cone-based planning and proton plans to evaluate their dosimetric advantages. Methods: The Vero treatment has unique features like no rotational or translational movements of the table during treatments, Dynamic Arc/IMRT, tracking of IR markers, limitation of Ring rotation. Accuracies of the image fusions using CBCT, orthogonal x-rays, and CT are evaluated less than ? 0.7mm with a custom-made target phantom with 18 hidden targets. 1mm margin is given to GTV to determine PTV for planning constraints considering all the uncertainties of planning computer and mechanical uncertainties of the treatment unit. Also, double-scattering proton plans with 6F to 9F beams and typical clinical parameters, multiple isocenter plans with 6 to 21 isocenters, and DA/IMRT plans are evaluated to investigate the dosimetric advantages of the DA/IMRT for complex shape of targets. Results: 3 Groups of the patients are divided: (1) Group A (complex target shape), CI's are same for IMRT, and DGI of the proton plan are better by 9.5% than that of the IMRT, (2) Group B, CI of the DA plans (1.91+/?0.4) are better than cone-based plan, while DGI of the DA plan is 4.60+/?1.1 is better than cone-based plan (5.32+/?1.4), (3) Group C (small spherical targets), CI of the DA and cone-based plans are almost the same. Conclusion: For small spherical targets, cone-based plans are superior to other 2 plans: DS proton and DA plans. For complex or irregular plans, dynamic and IMRT plans are comparable to cone-based and proton plans for complex targets.

  11. Arc Position Sensing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12Arah SchuurArc

  12. Cathodic Vacuum Arc Plasma of Thallium

    E-Print Network [OSTI]

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01T23:59:59.000Z

    P. J. Martin, Handbook of Vacuum Arc Science and Technology.charge state distributions of vacuum arc plasmas: The originand the broadening of vacuum-arc ion charge state

  13. Laser Assisted Plasma Arc Welding

    SciTech Connect (OSTI)

    FUERSCHBACH,PHILLIP W.

    1999-10-05T23:59:59.000Z

    Experiments have been performed using a coaxial end-effecter to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (< 1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  14. Arc fault detection system

    DOE Patents [OSTI]

    Jha, Kamal N. (Bethel Park, PA)

    1999-01-01T23:59:59.000Z

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

  15. Arc fault detection system

    DOE Patents [OSTI]

    Jha, K.N.

    1999-05-18T23:59:59.000Z

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

  16. ELSEVIER Thin Solid Films 260 (1995)205-211 Investigation of the atomic-scale friction and energy dissipation in

    E-Print Network [OSTI]

    Brenner, Donald W.

    dissipation in diamond using molecular dynamics Judith A. Harrisona, Carter T. Whiteb, Richard J. Coltonb;accepted 10 January 1995 Abstract We have used molecular dynamics simulations to examine friction when two to be the mechanical excitation (in the form of vibrational and rotational energy) of the interface lattice layers upon

  17. Oxygen and Nitrogen Contamination During Arc Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, shielded metal arc, self-shielded metal arc, and submerged arc welding are reviewed. Calcu- lations upon heating is also discussed. Introduction Oxygen and nitrogen ~ontamination of weld metal

  18. Percussive arc welding apparatus

    DOE Patents [OSTI]

    Hollar, Jr., Donald L. (Overland Park, KS)

    2002-01-01T23:59:59.000Z

    A percussive arc welding apparatus includes a generally cylindrical actuator body having front and rear end portions and defining an internal recess. The front end of the body includes an opening. A solenoid assembly is provided in the rear end portion in the internal recess of the body, and an actuator shaft assembly is provided in the front end portion in the internal recess of the actuator body. The actuator shaft assembly includes a generally cylindrical actuator block having first and second end portions, and an actuator shaft having a front end extending through the opening in the actuator body, and the rear end connected to the first end portion of the actuator block. The second end portion of the actuator block is in operational engagement with the solenoid shaft by a non-rigid connection to reduce the adverse rebound effects of the actuator shaft. A generally transversely extending pin is rigidly secured to the rear end of the shaft. One end of the pin is received in a slot in the nose housing sleeve to prevent rotation of the actuator shaft during operation of the apparatus.

  19. High pressure neon arc lamp

    DOE Patents [OSTI]

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15T23:59:59.000Z

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  20. Waste Heat Recovery – Submerged Arc Furnaces (SAF)

    E-Print Network [OSTI]

    O'Brien, T.

    2008-01-01T23:59:59.000Z

    Waste Heat Recovery- Submerged Arc Furnaces (SAF) Thomas O?Brien Recycled Energy Development, LLC tobrien@recycled-energy.com Submerged Arc Furnaces are used to produce high temperature alloys. These furnaces typically run at 3000oF using...

  1. Laboratory experiments on arc deflection and instability

    SciTech Connect (OSTI)

    Zweben, S.; Karasik, M.

    2000-03-21T23:59:59.000Z

    This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

  2. Metal vapor arc ion plating

    DOE Patents [OSTI]

    Bertram, L.A.; Fisher, R.W.; Mattox, D.M.; Zanner, F.J.

    1986-09-09T23:59:59.000Z

    A method and apparatus for ion plating are described. The apparatus uses more negative than a first electrode voltage in a vacuum arc remelt system to attract low energy ions from the anode electrode to the article to be plated. 2 figs.

  3. Atomic scale insight into the amorphous structure of Cu doped GeTe phase-change material

    SciTech Connect (OSTI)

    Zhang, Linchuan; Sa, Baisheng [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Zhou, Jian; Sun, Zhimei, E-mail: zmsun@buaa.edu.cn [School of Materials Science and Engineering, and Center for Integrated Computational Materials Engineering, International Research Institute for Multidisciplinary Science, Beihang University, Beijing 100191 (China); Song, Zhitang [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, CAS, 200050 Shanghai (China)

    2014-10-21T23:59:59.000Z

    GeTe shows promising application as a recording material for phase-change nonvolatile memory due to its fast crystallization speed and extraordinary amorphous stability. To further improve the performance of GeTe, various transition metals, such as copper, have been doped in GeTe in recent works. However, the effect of the doped transition metals on the stability of amorphous GeTe is not known. Here, we shed light on this problem for the system of Cu doped GeTe by means of ab initio molecular dynamics calculations. Our results show that the doped Cu atoms tend to agglomerate in amorphous GeTe. Further, base on analyzing the pair correlation functions, coordination numbers and bond angle distributions, remarkable changes in the local structure of amorphous GeTe induced by Cu are obviously seen. The present work may provide some clues for understanding the effect of early transition metals on the local structure of amorphous phase-change compounds, and hence should be helpful for optimizing the structure and performance of phase-change materials by doping transition metals.

  4. Atomic-scale modification of hybrid FePt cluster-assembled films A. N. Dobrynin, D. N. Ievlev, G. Verschoren, J. Swerts, M. J. Van Bael, K. Temst, and P. Lievens*

    E-Print Network [OSTI]

    Dobrynin, Alexey

    Atomic-scale modification of hybrid FePt cluster-assembled films A. N. Dobrynin, D. N. Ievlev, G in the context of hybrid magnetic systems, e.g., exchange spring magnets,3,4 and exchange-biased systems.5 storage.1 During the last few years iron-platinum FePt nanopar- ticles and nanocomposites were widely

  5. Filters for cathodic arc plasmas

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA); Bilek, Marcela M. M. (Engadine, AU); Brown, Ian G. (Berkeley, CA)

    2002-01-01T23:59:59.000Z

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  6. Atomic scale studies of the chemistry of the Cu/MgO {l_brace}111{r_brace} heterophase interface

    SciTech Connect (OSTI)

    Jang, H.; Seidman, D.N. [Northwestern Univ., Evanston, IL (United States); Merkle, K.L. [Argonne National Lab., IL (United States)

    1992-08-01T23:59:59.000Z

    The Cu/MgO [111] heterophase interface is studied using a combination of transmission electron microscopy, high resolution electron microscopy and atom-probe field-ion microscopy techniques. Wire and foil specimens of a Cu-2.8 at.% Mg alloy were internally oxidized to produce MgO precipitates at a number density of 5{center_dot}10{sup 15}Cm{sup {minus}3} with a mean diameter of {approx}200 {Angstrom}. The MgO precipitates have a semicoherent interface with the Cu matrix and they exhibit a cube-on-cube orientation relationship. The octahedral-shaped MgO precipitates were analyzed using APFIM by dissecting along a <111> direction on an atomic scale. In this manner an MgO precipitate, with a [111] plane perpendicular to the axis of the APFIM, is uncovered after the Cu matrix has been mass analyzed. It was found that the terminating [222] plane of an MgO precipitate is pure oxygen, and the second [222] plane is pure Mg.

  7. Stability measurements of PPL atmospheric pressure arc

    SciTech Connect (OSTI)

    Roquemore, L.; Zweben, S.J. [Princeton Plasma Physics Lab., NJ (United States); Wurden, G.A. [Los Alamos National Lab., NM (United States)

    1997-12-31T23:59:59.000Z

    Experiments on the stability of atmospheric pressure arcs have been started at PPL to understand and improve the performance of arc furnaces used for processing applications in metallurgy and hazardous waste treatment. Previous studies have suggested that the violent instabilities in such arcs may be due to kink modes. A 30 kW, 500 Amp CW DC experimental arc furnace was constructed with a graphite cathode and a molten steel anode. The arc plasma is diagnosed with 4000 frames/sec digital camera, Hall probes, and voltage and current monitors. Under certain conditions, the arc exhibits an intermittent helical instability, with the helix rotating at {approx}600 Hz. The nature of the instability is investigated. A possible instability mechanism is the self-magnetic field of the arc, with saturation occurring due to inhomogeneous heating in a helical arc. The effect of external DC and AC magnetic fields on the instability is investigated. Additionally, arc deflection due to external transverse magnetic field is investigated. The deflection angle is found to be proportional to the applied field, and is in good agreement with a simple model of the {rvec J} x {rvec b} force on the arc jet.

  8. Plasma arc torch with coaxial wire feed

    DOE Patents [OSTI]

    Hooper, Frederick M (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  9. ARC-ED Curriculum: The Application of Video Game Formats to Educational Software

    E-Print Network [OSTI]

    Chaffin, Jerry D.; Maxwell, Bill; Thompson, Barbara

    1982-01-01T23:59:59.000Z

    educational practices are examined in relation to the motivational features of arcade games. Also, guidelines for educational curriculum based on arcade game formats are proposed and the term Arc-Ed Curriculum is offered to describe such software. The content...

  10. Linkage of the ArcHydro Data Model with SWAT

    E-Print Network [OSTI]

    Linkage of the ArcHydro Data Model with SWAT Francisco Olivera, Ph.D., P.E. Milver Valenzuela Texas on a hub basis. Independent of the already connected models HUB #12;Arc Hydro Arc Hydro can be used as the hub for connecting hydrologic models. #12;Arc Hydro #12;What it is and what it is not ... Arc Hydro

  11. Metals purification by improved vacuum arc remelting

    DOE Patents [OSTI]

    Zanner, Frank J. (Sandia Park, NM); Williamson, Rodney L. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    1994-12-13T23:59:59.000Z

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  12. Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and

    E-Print Network [OSTI]

    Sengupta, Raja

    Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and MODPATH Abstract Modeling. This paper addresses groundwater modeling which is one of the many entities in environmental modeling in ArcView 3.2a. The objective was to create an integrated system where a user could do groundwater

  13. Miniaturized cathodic arc plasma source

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

    2003-04-15T23:59:59.000Z

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  14. Plasma arc melting of zirconium

    SciTech Connect (OSTI)

    Tubesing, P.K.; Korzekwa, D.R.; Dunn, P.S.

    1997-12-31T23:59:59.000Z

    Zirconium, like some other refractory metals, has an undesirable sensitivity to interstitials such as oxygen. Traditionally, zirconium is processed by electron beam melting to maintain minimum interstitial contamination. Electron beam melted zirconium, however, does not respond positively to mechanical processing due to its large grain size. The authors undertook a study to determine if plasma arc melting (PAM) technology could be utilized to maintain low interstitial concentrations and improve the response of zirconium to subsequent mechanical processing. The PAM process enabled them to control and maintain low interstitial levels of oxygen and carbon, produce a more favorable grain structure, and with supplementary off-gassing, improve the response to mechanical forming.

  15. True atomic-scale imaging of a spinel Li{sub 4}Ti{sub 5}O{sub 12}(111) surface in aqueous solution by frequency-modulation atomic force microscopy

    SciTech Connect (OSTI)

    Kitta, Mitsunori, E-mail: m-kitta@aist.go.jp; Kohyama, Masanori [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Onishi, Hiroshi [Department of Chemistry, Graduate School of Science, Kobe University 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-09-15T23:59:59.000Z

    Spinel-type lithium titanium oxide (LTO; Li{sub 4}Ti{sub 5}O{sub 12}) is a negative electrode material for lithium-ion batteries. Revealing the atomic-scale surface structure of LTO in liquid is highly necessary to investigate its surface properties in practical environments. Here, we reveal an atomic-scale image of the LTO(111) surface in LiCl aqueous solution using frequency-modulation atomic force microscopy. Atomically flat terraces and single steps having heights of multiples of 0.5?nm were observed in the aqueous solution. Hexagonal bright spots separated by 0.6?nm were also observed on the flat terrace part, corresponding to the atomistic contrast observed in the ultrahigh vacuum condition, which suggests that the basic atomic structure of the LTO(111) surface is retained without dramatic reconstruction even in the aqueous solution.

  16. Purification of tantalum by plasma arc melting

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Korzekwa, Deniece R. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.

  17. Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines...

  18. antilles island arc: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The morphology of the underthrust oceanic crust controls the mag matic activity of the island arc, and particularly the development, in space and time, of "arc compartments." Denis...

  19. Type B Accident Investigation of the Arc Flash at Brookhaven...

    Broader source: Energy.gov (indexed) [DOE]

    Arc Flash at Brookhaven National Laboratory, April 14, 2006 Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006 February 10, 2006 An...

  20. Laser assisted arc welding for aluminum alloys

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    2000-01-01T23:59:59.000Z

    Experiments have been performed using a coaxial end-effector to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (<1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  1. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1987-11-17T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

  2. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  3. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1985-08-05T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  4. Theoretical analysis of ARC constriction

    SciTech Connect (OSTI)

    Stoenescu, M.L.; Brooks, A.W.; Smith, T.M.

    1980-12-01T23:59:59.000Z

    The physics of the thermionic converter is governed by strong electrode-plasma interactions (emissions surface scattering, charge exchange) and weak interactions (diffusion, radiation) at the maximum interelectrode plasma radius. The physical processes are thus mostly convective in thin sheaths in front of the electrodes and mostly diffusive and radiative in the plasma bulk. The physical boundaries are open boundaries to particle transfer (electrons emitted or absorbed by the electrodes, all particles diffusing through some maximum plasma radius) and to convective, conductive and radiative heat transfer. In a first approximation the thermionic converter may be described by a one-dimensional classical transport theory. The two-dimensional effects may be significant as a result of the sheath sensitivity to radial plasma variations and of the strong sheath-plasma coupling. The current-voltage characteristic of the converter is thus the result of an integrated current density over the collector area for which the boundary conditions at each r determine the regime (ignited/unignited) of the local current density. A current redistribution strongly weighted at small radii (arc constriction) limits the converter performance and opens questions on constriction reduction possibilities. The questions addressed are the followng: (1) what are the main contributors to the loss of current at high voltage in the thermionic converter; and (2) is arc constriction observable theoretically and what are the conditions of its occurrence. The resulting theoretical problem is formulated and results are given. The converter electrical current is estimated directly from the electron and ion particle fluxes based on the spatial distribution of the electron/ion density n, temperatures T/sub e/, T/sub i/, electrical voltage V and on the knowledge of the transport coefficients. (WHK)

  5. Palaeoproterozoic arc magmatism and collision in Liaodong Peninsula (north-east China)

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Palaeoproterozoic arc magmatism and collision in Liaodong Peninsula (north-east China) Michel Faure, LTE, Chinese Academy of Sciences PO Box 9525 Beijing, 100029, China; 3 Department of Earth-eastern China and discusses its possible geo- dynamic setting in terms of subduc- tion and collision. Geological

  6. Investigation of arc length versus flange thickness while using an arc voltage controller

    SciTech Connect (OSTI)

    Daumeyer, G.J.

    1994-11-01T23:59:59.000Z

    An arc voltage controller (AVC) for gas tungsten arc welding will change arc length when flange thickness changes while all other variables, including AVC setting, are held constant. A procedure for calibrating an LVDT (linear variable displacement transducer) used for electrode assembly motion monitoring was proven for laboratory setups and special investigations. A partial characterization on the deadband and sensitivity control settings of the Cyclomatic AVC was completed.

  7. Arc distribution during the vacuum arc remelting of Ti-6Al-4V

    SciTech Connect (OSTI)

    Woodside, Charles Rigel [U.S. DOE; King, Paul E. [U.S. DOE; Nordlund, Chris [ATI Albany Operations

    2013-01-01T23:59:59.000Z

    Currently, the temporal distribution of electric arcs across the ingot during vacuum arc remelting (VAR) is not a known or monitored process parameter. Previous studies indicate that the distribution of arcs can be neither diffuse nor axisymmetric about the center of the furnace. Correct accounting for the heat flux, electric current flux, and mass flux into the ingot is critical to achieving realistic solidification models of the VAR process. The National Energy Technology Laboratory has developed an arc position measurement system capable of locating arcs and determining the arc distribution within an industrial VAR furnace. The system is based on noninvasive magnetic field measurements and a VAR specific form of the Biot–Savart law. The system was installed on a coaxial industrial VAR furnace at ATI Albany Operations in Albany, OR. This article reports on the different arc distributions observed during production of Ti-6Al-4V. It is shown that several characteristic arc distribution modes can develop. This behavior is not apparent in the existing signals used to control the furnace, indicating the measurement system is providing new information. It is also shown that the different arc distribution modes observed may impact local solidification times, particularly at the side wall.

  8. Detection of arcs in automotive electrical systems

    E-Print Network [OSTI]

    Mishrikey, Matthew David

    2005-01-01T23:59:59.000Z

    At the present time, there is no established method for the detection of DC electric arcing. This is a concern for forthcoming advanced automotive electrical systems which consist of higher DC electric power bus voltages, ...

  9. Heat transfer in gas tungsten arc welding

    SciTech Connect (OSTI)

    Smartt, H.B.; Stewart, J.A.; Einerson, C.J.

    1986-05-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode has been measured for a wide range of conditions suitable for mechanized welding applications. The results are given as (1) the arc efficiency; and (2) the anode heat and current input distribution functional shapes and radii for various anode materials and groove shapes over a wide range of current and voltage, using different electrode geometries, as well as both He and Ar-He shielding gases. The nominal arc is Gaussian with a diameter of about 4 mm and a heat transfer efficiency to the anode of about 75%. Variations from these values are discussed in terms of current knowledge of the electrical and thermal energy transport mechanisms. A new method of measuring the heat transferred from the arc to the anode, using a boiling liquid nitrogen calorimeter, has been developed which gives rapid, accurate values.

  10. The arc cloud complex: a case study

    E-Print Network [OSTI]

    Miller, Robert Loren

    1984-01-01T23:59:59.000Z

    THE ARC CLOUD COMPLEX: A CASE STUDY A Thesis by ROBERT LOREN MILLER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1984 Major Subject...: Meteorology THE ARC CLOUD COMPLEX; A CASE STUDY A Thesis by ROBERT LOREN MILLER Approved as to style and content by: Kenneth C. Brundidge (Chairman of Committee) Walter K. Henry (Member) Marshall ~ Mcparland (Member) James R. Scog s (Head...

  11. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, William K. (Oak Ridge, TN)

    1985-01-01T23:59:59.000Z

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power, thereby preventing the exposure of the anode to the full arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  12. ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep

    E-Print Network [OSTI]

    Zhang, YuMing

    ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep penetration. To ensure the quality of the welds, the presence of the keyhole is crit- ical. Understanding of the keyhole will certainly benefit the improvement of the process and weld quality. Currently, the size of the keyhole

  13. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, W.K.

    1983-12-16T23:59:59.000Z

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  14. Ion source based on the cathodic arc

    DOE Patents [OSTI]

    Sanders, D.M.; Falabella, S.

    1994-02-01T23:59:59.000Z

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

  15. Arc Geometry and Algebra: Foliations, Moduli ... - Purdue University

    E-Print Network [OSTI]

    2012-07-04T23:59:59.000Z

    the simplicial complex which has one simplex for each arc family ? with the i–the face ..... 1.6.2 Loop graph of an arc family: A geometric construction of the dual.

  16. NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES Michel Bellet 1 , Makhlouf Antipolis, France; soudage@transvalor.com Keywords: welding, finite elements, material deposit, adaptive for arc welding simulation and analysis. The new numerical technologies essentially consist first

  17. arc ion sources: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and performance of vacuum arc ion sources. Brown, I 2013-01-01 2 Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde CERN Preprints Summary: We...

  18. arc ion source: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and performance of vacuum arc ion sources. Brown, I 2013-01-01 2 Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde CERN Preprints Summary: We...

  19. Correlations between SAR arc intensity and solar and geomagnetic activity

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ±1960, Rees and Akasofu (1963) and Roach and Roach (1963) found that there are correlations of the SAR arc

  20. The Inception of the ArcGIS Marine Data Model

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    . Shapefiles and coverages can now be easily loaded as feature classes in the ArcGISTM geodatabase for more

  1. Way to reduce arc voltage losses in hybrid thermionic converters

    SciTech Connect (OSTI)

    Tskhakaya, V.K.; Yarygin, V.I.

    1982-03-01T23:59:59.000Z

    Experimental results are reported concerning the output and emission characteristics of the arc and hybrid regimes in a plane-parallel thermionic converter with Pt--Zr--O electrode pair. It is shown that arc voltage losses can be reduced to values below those obtainable in ordinary arc thermionic converters.

  2. Evaluation of the clinical usefulness of modulated Arc treatment

    E-Print Network [OSTI]

    Lee, Young Kyu; Kim, Yeon Sil; Choi, Byung Ock; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; Park, Sung Kwang; Kim, Jin Young; Kang, Young-Nam

    2015-01-01T23:59:59.000Z

    The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans of the non-small cell lung cancer (NSCLC) patients were performed in order to verify the clinical usefulness of mARC. A pre study was conducted to find the most competent plan condition of mARC treatment and the usefulness of mARC treatment plan was evaluated by comparing it with the other Arc treatment plans such as Tomotherapy and RapidArc. In the case of mARC, the optimal condition for the mARC plan was determined by comparing the dosimetric performance of the mARC plans with the use of various parameters. The various parameters includes the photon energies (6 MV, 10 MV), optimization point angle (6{\\deg}-10{\\deg} intervals), and total segment number (36-59 segment). The best dosimetric performance of mARC was observed at 10 MV photon energy and the point angle 6 degree, and 59 segments. The each treatment plans of three different techniques were compared with the followin...

  3. Costing of Joining Methods -Arc Welding Costs

    E-Print Network [OSTI]

    Colton, Jonathan S.

    Costing of Joining Methods - Arc Welding Costs ver. 1 ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 1 #12;OverviewOverview · Cost components · Estimation of costsEstimation of costs · Examples ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 2 #12;Cost

  4. Energy Savings in Electric Arc Furnace Melting

    E-Print Network [OSTI]

    Lubbeck, W.

    1982-01-01T23:59:59.000Z

    Arc furnace melting which at one time was almost exclusively used to produce alloy steel and steel castings is now widely accepted in the industry as an efficient process to produce all types of steel and iron. Presently, about 28% of steel...

  5. Gas tungsten arc welder with electrode grinder

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Brown, William F. (West Richland, WA)

    1984-01-01T23:59:59.000Z

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  6. Pairing, pseudogap and Fermi arcs in cuprates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kaminski, Adam; Gu, Genda; Kondo, Takeshi; Takeuchi, Tsunehiro

    2014-10-31T23:59:59.000Z

    We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scatteringmore »creates “artificial” Fermi arcs for Tc pair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.« less

  7. Driven Motion and Instability of an Atmospheric Pressure Arc

    SciTech Connect (OSTI)

    Max Karasik

    1999-12-01T23:59:59.000Z

    Atmospheric pressure arcs are used extensively in applications such as welding and metallurgy. However, comparatively little is known of the physics of such arcs in external magnetic fields and the mechanisms of the instabilities present. In order to address questions of equilibrium and stability of such arcs, an experimental arc furnace is constructed and operated in air with graphite cathode and steel anode at currents 100-250 A. The arc is diagnosed with a gated intensified camera and a collimated photodiode array, as well as fast voltage and current probes.

  8. Multiphysics Modeling and Simulations of Mil A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding Process M. Grujicic, S. Ramaswami, J.S. Snipes, C.-F. Yen, B.A. Cheeseman, and J.S. Montgomery developed for the conventional Gas Metal Arc Welding (GMAW) joining process and used to analyze butt-welding modules, each covering a specific aspect of the GMAW process, i.e., (a) dynamics of welding-gun behavior

  9. Electrical Safety and Arc Flash Protections

    SciTech Connect (OSTI)

    R. Camp

    2008-03-04T23:59:59.000Z

    Over the past four years, the Electrical Safety Program at PPPL has evolved in addressing changing regulatory requirements and lessons learned from accident events, particularly in regards to arc flash hazards and implementing NFPA 70E requirements. This presentation will discuss PPPL's approaches to the areas of electrical hazards evaluation, both shock and arc flash; engineered solutions for hazards mitigation such as remote racking of medium voltage breakers, operational changes for hazards avoidance, targeted personnel training and hazard appropriate personal protective equipment. Practical solutions for nominal voltage identification and zero voltage checks for lockout/tagout will also be covered. Finally, we will review the value of a comprehensive electrical drawing program, employee attitudes expressed as a personal safety work ethic, integrated safety management, and sustained management support for continuous safety improvement.

  10. Recent advances in vacuum arc ion sources

    SciTech Connect (OSTI)

    Brown, I.G.; Anders, A.; Anders, S.; Dickinson, M.R.; MacGill, R.A.; Oks, E.M.

    1995-07-01T23:59:59.000Z

    Intense beams of metal ions can be formed from a vacuum arc ion source. Broadbeam extraction is convenient, and the time-averaged ion beam current delivered downstream can readily be in the tens of milliamperes range. The vacuum arc ion source has for these reasons found good application for metallurgical surface modification--it provides relatively simple and inexpensive access to high dose metal ion implantation. Several important source developments have been demonstrated recently, including very broad beam operation, macroparticle removal, charge state enhancement, and formation of gaseous beams. The authors have made a very broad beam source embodiment with beam formation electrodes 50 cm in diameter, producing a beam of width {approximately}35 cm for a nominal beam area of {approximately}1,000 cm{sup 2}, and a pulsed Ti beam current of about 7 A was formed at a mean ion energy of {approximately}100 keV. Separately, they`ve developed high efficiency macroparticle-removing magnetic filters and incorporated such a filter into a vacuum arc ion source so as to form macroparticle-free ion beams. Jointly with researchers at the High Current Electronics Institute at Tomsk, Russia, and the Gesellschaft fuer Schwerionenforschung at Darmstadt, Germany, they`ve developed a compact technique for increasing the charge states of ions produced in the vacuum arc plasma and thus providing a simple means of increasing the ion energy at fixed extractor voltage. Finally, operation with mixed metal and gaseous ion species has been demonstrated. Here, they briefly review the operation of vacuum marc ion sources and the typical beam and implantation parameters that can be obtained, and describe these source advances and their bearing on metal ion implantation applications.

  11. Arc melter demonstration baseline test results

    SciTech Connect (OSTI)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; Oden, L.L.; O`Connor, W.K.; Turner, P.C.

    1994-07-01T23:59:59.000Z

    This report describes the test results and evaluation for the Phase 1 (baseline) arc melter vitrification test series conducted for the Buried Waste Integrated Demonstration program (BWID). Phase 1 tests were conducted on surrogate mixtures of as-incinerated wastes and soil. Some buried wastes, soils, and stored wastes at the INEL and other DOE sites, are contaminated with transuranic (TRU) radionuclides and hazardous organics and metals. The high temperature environment in an electric arc furnace may be used to process these wastes to produce materials suitable for final disposal. An electric arc furnace system can treat heterogeneous wastes and contaminated soils by (a) dissolving and retaining TRU elements and selected toxic metals as oxides in the slag phase, (b) destroying organic materials by dissociation, pyrolyzation, and combustion, and (c) capturing separated volatilized metals in the offgas system for further treatment. Structural metals in the waste may be melted and tapped separately for recycle or disposal, or these metals may be oxidized and dissolved into the slag. The molten slag, after cooling, will provide a glass/ceramic final waste form that is homogeneous, highly nonleachable, and extremely durable. These features make this waste form suitable for immobilization of TRU radionuclides and toxic metals for geologic timeframes. Further, the volume of contaminated wastes and soils will be substantially reduced in the process.

  12. Dosimetric evaluation of the interplay effect in respiratory-gated RapidArc radiation therapy

    SciTech Connect (OSTI)

    Riley, Craig [Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213 (United States)] [Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213 (United States); Yang, Yong, E-mail: yangy2@upmc.edu; Li, Tianfang; Zhang, Yongqian; Heron, Dwight E.; Huq, M. Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States)] [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States)

    2014-01-15T23:59:59.000Z

    Purpose: Volumetric modulated arc therapy (VMAT) with gating capability has had increasing adoption in many clinics in the United States. In this new technique, dose rate, gantry rotation speed, and the leaf motion speed of multileaf collimators (MLCs) are modulated dynamically during gated beam delivery to achieve highly conformal dose coverage of the target and normal tissue sparing. Compared with the traditional gated intensity-modulated radiation therapy technique, this complicated beam delivery technique may result in larger dose errors due to the intrafraction tumor motion. The purpose of this work is to evaluate the dosimetric influence of the interplay effect for the respiration-gated VMAT technique (RapidArc, Varian Medical Systems, Palo Alto, CA). Our work consisted of two parts: (1) Investigate the interplay effect for different target residual errors during gated RapidArc delivery using a one-dimensional moving phantom capable of producing stable sinusoidal movement; (2) Evaluate the dosimetric influence in ten clinical patients’ treatment plans using a moving phantom driven with a patient-specific respiratory curve. Methods: For the first part of this study, four plans were created with a spherical target for varying residual motion of 0.25, 0.5, 0.75, and 1.0 cm. Appropriate gating windows were applied for each. The dosimetric effect was evaluated using EDR2 film by comparing the gated delivery with static delivery. For the second part of the project, ten gated lung stereotactic body radiotherapy cases were selected and reoptimized to be delivered by the gated RapidArc technique. These plans were delivered to a phantom, and again the gated treatments were compared to static deliveries by the same methods. Results: For regular sinusoidal motion, the dose delivered to the target was not substantially affected by the gating windows when evaluated with the gamma statistics, suggesting the interplay effect has a small role in respiratory-gated RapidArc therapy. Varied results were seen when gated therapy was performed on the patient plans that could only be attributed to differences in patient respiratory patterns. Patients whose plans had the largest percentage of pixels failing the gamma statistics exhibited irregular breathing patterns including substantial interpatient variation in depth of respiration. Conclusions: The interplay effect has a limited impact on gated RapidArc therapy when evaluated with a linear phantom. Variations in patient breathing patterns, however, are of much greater clinical significance. Caution must be taken when evaluating patients’ respiratory efforts for gated arc therapy.

  13. Rapid mapping tool : an ArcMap extension /

    SciTech Connect (OSTI)

    Linger, S. P. (Steve P.); Rich, P. M. (Paul M.); Walther, D. (Douglas); Witkowski, M. S. (Marc S.); Jones, M. A. (Marcia A.); Khalsa, H. S. (Hari S.)

    2002-01-01T23:59:59.000Z

    Cartographic production laboratories produce large volumes of maps for diverse customers. Turnaround time and consistency are key concerns. The Rapid Mapping Tool is an ArcMap based tool that enables rapid creation of maps to meet customer needs. This tool was constructed using VB/VBA, ArcObjects, and ArcGIS templates. The core capability of ArcMap is extended for custom map production by storing specifications associated with a map or template in a companion XML document. These specifications include settings and preferences used to create custom maps. The tool was developed as a component of an enterprise GIS, which enables spatial data management and delivery using ArcSDE, ArcIMS, Oracle, and a web-based request tracking system.

  14. Order Reduction of the Radiative Heat Transfer Model for the Simulation of Plasma Arcs

    E-Print Network [OSTI]

    Fagiano, Lorenzo

    2015-01-01T23:59:59.000Z

    An approach to derive low-complexity models describing thermal radiation for the sake of simulating the behavior of electric arcs in switchgear systems is presented. The idea is to approximate the (high dimensional) full-order equations, modeling the propagation of the radiated intensity in space, with a model of much lower dimension, whose parameters are identified by means of nonlinear system identification techniques. The low-order model preserves the main structural aspects of the full-order one, and its parameters can be straightforwardly used in arc simulation tools based on computational fluid dynamics. In particular, the model parameters can be used together with the common approaches to resolve radiation in magnetohydrodynamic simulations, including the discrete-ordinate method, the P-N methods and photohydrodynamics. The proposed order reduction approach is able to systematically compute the partitioning of the electromagnetic spectrum in frequency bands, and the related absorption coefficients, tha...

  15. Influence of argon and oxygen on charge-state-resolved ion energy distributions of filtered aluminum arcs

    E-Print Network [OSTI]

    Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-01-01T23:59:59.000Z

    energy distributions of filtered aluminum arcs Johanna Roséndistributions (IEDs) in filtered aluminum vacuum arc plasmasfor vacuum arc plasmas. Aluminum plasma, for example,

  16. Molecular Dynamics Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    low viscosity of the brine. 16 The primary disadvantage of an aqueous electrolyte supercapacitor is the limitation of the electric potential to 1 V. 17 Atomic scale...

  17. arc welding dynamic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Materials Science Websites Summary: diffusivity specific heat thermal conductivity 2 operating parameter (n qv 4a p Tc - T0 net heat i nput- CHANGES OF WELD POOL SHAPE BY...

  18. arc generated carbon: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    as a single storage endpoint and a pool of distributed computing nodes. The next generation ARC middleware with its several new technologies provides new possibilities in...

  19. arc magmatism isotopic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    J. 3 TECTONIC CONTROLS OF GEOCHEMICAL EVOLUTION IN ARC MAGMATISM OF SE ASIA 359Bali, Indonesia, 10 -13 October 1999PACRIM 99 Geosciences Websites Summary: processes operating at...

  20. andean arc magmatism: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    J. 3 TECTONIC CONTROLS OF GEOCHEMICAL EVOLUTION IN ARC MAGMATISM OF SE ASIA 359Bali, Indonesia, 10 -13 October 1999PACRIM 99 Geosciences Websites Summary: processes operating at...

  1. arc lamp heal: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cultures) -- (Animal Behaviour Wang, Yan 40 Spatial and time-dependent distribution of plasma parameters in the metal-halide arc lamp. Physics Websites Summary: for the...

  2. PV Arc Fault Detector Challenges Due to Module Frequency Response...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    This poster does not contain any proprietary or confidential information. Introduction PV system arc faults have led to a number of rooftop fires which have caused significant...

  3. PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL LABORATORIES Jay Johnson 1 , Birger Pahl 2 , Charles Luebke 2 , Tom Pier 2 , Theodore Miller 3 , Jason Strauch 1 ,...

  4. Sandia National Laboratories: photovoltaic direct-current arc...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Program Goals IndustryCollaboration FutureCollaborations Publications Contacts Photovoltaic (PV) arc-faults can lead to fires, damage property, and threaten the safety of...

  5. Dynamic

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling7111AWell: Gas productionDynamic , and Static ,

  6. Hydrologic Modeling with Arc Hydro Tools 1 Copyright 2007 ESRI. All rights reserved. Arc Hydro

    E-Print Network [OSTI]

    Kane, Andrew S.

    resources applications (template data model) Culmination of a three year process led by D.R. Maidment rights reserved. Inside the Geodatabase Geodatabase Survey datasets Survey folder Survey Locators Template Data Models (30+) HEC ...FEMA Project Data Models Feature TopologyObject ArcGIS Core Data Model

  7. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, Herschel B. (Idaho Falls, ID); Einerson, Carolyn J. (Idaho Falls, ID); Watkins, Arthur D. (Idaho Falls, ID)

    1989-01-01T23:59:59.000Z

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

  8. The ATLAS ARC backend to HPC

    E-Print Network [OSTI]

    Haug, Sigve; The ATLAS collaboration; Sciacca, Francesco Giovanni; Weber, Michele

    2015-01-01T23:59:59.000Z

    The current distributed computing resources used for simulating and processing collision data collected by the LHC experiments are largely based on dedicated x86 Linux clusters. Access to resources, job control and software provisioning mechanisms are quite different from the common concept of self-contained HPC applications run by particular users on specific HPC systems. We report on the development and the usage of a ssh back-end to the Advanced Resource Connector (ARC) middleware to enable HPC compliant access and on the corresponding software provisioning mechanisms.

  9. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

    1987-08-10T23:59:59.000Z

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

  10. ScanArc ASA | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with form HistoryRistma AG Jump638324°, -122.0230146° ShowSavannahSavvasScanArc

  11. Constraints on the composition of the Aleutian arc lower crust from

    E-Print Network [OSTI]

    Shillington, Donna J.

    Determining the bulk composition of island arc lower crust is essential for distinguishing between competing models for arc magmatism and assessing the stability of arc lower crust. We present new constraints on the ...

  12. arc welding automation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    arc welding automation First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Double-Sided Arc Welding...

  13. arc plasma torch: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: periodA, sagitta in dipoles dipSag." arc2Table::usage "arc2Table R,cirC,pA,pL,phA,,, prints a table periodA, sagitta in dipoles dipSag." Begin "Private"...

  14. arc plasma torches: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: periodA, sagitta in dipoles dipSag." arc2Table::usage "arc2Table R,cirC,pA,pL,phA,,, prints a table periodA, sagitta in dipoles dipSag." Begin "Private"...

  15. What makes an electric welding arc perform its required function

    SciTech Connect (OSTI)

    Correy, T.B.

    1982-09-01T23:59:59.000Z

    The physics of direct current and alternating current welding arcs, the heat transfer of direct current welding arcs, the characteristics of dc welding and ac welding power supplies and recommendations for the procurement and maintenance of precision power supplies are discussed. (LCL)

  16. E-Print Network 3.0 - arc discharge method Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at different points on the cable. The discharge contained short, bluish arcs. 12... Artificial Dry-band Arcing ... Source: Arizona State University, Power Systems Engineering...

  17. Molecular dynamics simulation comparison of atomic scale intermixing at the amorphous Al2O3/semiconductor interface for a-Al2O3/Ge, a-Al2O3/InGaAs,

    E-Print Network [OSTI]

    Kummel, Andrew C.

    /semiconductor interface for a-Al2O3/Ge, a-Al2O3/InGaAs, and a-Al2O3/InAlAs/InGaAs Evgueni A. Chagarov *, Andrew oxides Ge InGaAs InAlAs Oxide­semiconductor stack High-K oxide a b s t r a c t The structural properties of a-Al2O3/Ge, a-Al2O3/In0.5Ga0.5As and a-Al2O3/In0.5Al0.5As/InGaAs interfaces were investigated

  18. No significant post-Eocene rotation of the Moesian Platform and Rhodope (Bulgaria): Implications for the kinematic evolution of the Carpathian and Aegean arcs

    E-Print Network [OSTI]

    Utrecht, Universiteit

    The region located between the Carpathian­Balkan and Aegean arcs, the Moesian Platform and Bulgarian Rhodope, orogenic collapse and subducted slab dynamics: the Aegean, Carpathian and Balkan orogenic systems (Fig. 1). Between the Carpathian and Balkan orogenic systems is the Moesian Platform, a Precambrian basement block

  19. Acoustic stabilization of electric arc instabilities in nontransferred plasma torches

    SciTech Connect (OSTI)

    Rat, V.; Coudert, J. F. [CNRS, University of Limoges, SPTCS UMR6638, 123 Avenue A. Thomas, 87060 Limoges Cedex (France)

    2010-03-08T23:59:59.000Z

    Electric arc instabilities in dc plasma torches lead to nonhomogeneous treatments of nanosized solid particles or liquids injected within thermal plasma jets. This paper shows that an additional acoustic resonator mounted on the cathode cavity allows reaching a significant damping of these instabilities, particularly the Helmholtz mode of arc oscillations. The acoustic resonator is coupled with the Helmholtz resonator of the plasma torch limiting the amplitude of arc voltage variations. It is also highlighted that this damping is dependent on friction effects in the acoustic resonator.

  20. THE PHYSICS OF ARC WELDING PROCESSES Department of Materials Science and Engineering,

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) THE PHYSICS OF ARC WELDING PROCESSES T.W.EAGAR Department of Materials Science and Engineering, Massachusetts Institute of Technology Abstract Welding is an extremely complex proce ss; however, due to its Wor ds: Arc Welding, Arc Physics, Shielding Gases, Gas Metal Arc Welding. 1. Introduction Langmuir

  1. Column generation heuristic for a rich arc routing Application to railroad track inspection routing

    E-Print Network [OSTI]

    Ingrand, François

    /LAAS) Optimising maintenance routing ATMOS 2010 7 / 24 #12;Literature review Industrial arc routing problems Hasle

  2. FusionArc optimization: A hybrid volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) planning strategy

    SciTech Connect (OSTI)

    Matuszak, Martha M.; McShan, Daniel L.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Steers, Jennifer M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 and Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Long, Troy; Edwin Romeijn, H. [Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Fraass, Benedick A. [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California 90048 (United States)

    2013-07-15T23:59:59.000Z

    Purpose: To introduce a hybrid volumetric modulated arc therapy/intensity modulated radiation therapy (VMAT/IMRT) optimization strategy called FusionArc that combines the delivery efficiency of single-arc VMAT with the potentially desirable intensity modulation possible with IMRT.Methods: A beamlet-based inverse planning system was enhanced to combine the advantages of VMAT and IMRT into one comprehensive technique. In the hybrid strategy, baseline single-arc VMAT plans are optimized and then the current cost function gradients with respect to the beamlets are used to define a metric for predicting which beam angles would benefit from further intensity modulation. Beams with the highest metric values (called the gradient factor) are converted from VMAT apertures to IMRT fluence, and the optimization proceeds with the mixed variable set until convergence or until additional beams are selected for conversion. One phantom and two clinical cases were used to validate the gradient factor and characterize the FusionArc strategy. Comparisons were made between standard IMRT, single-arc VMAT, and FusionArc plans with one to five IMRT/hybrid beams.Results: The gradient factor was found to be highly predictive of the VMAT angles that would benefit plan quality the most from beam modulation. Over the three cases studied, a FusionArc plan with three converted beams achieved superior dosimetric quality with reductions in final cost ranging from 26.4% to 48.1% compared to single-arc VMAT. Additionally, the three beam FusionArc plans required 22.4%-43.7% fewer MU/Gy than a seven beam IMRT plan. While the FusionArc plans with five converted beams offer larger reductions in final cost-32.9%-55.2% compared to single-arc VMAT-the decrease in MU/Gy compared to IMRT was noticeably smaller at 12.2%-18.5%, when compared to IMRT.Conclusions: A hybrid VMAT/IMRT strategy was implemented to find a high quality compromise between gantry-angle and intensity-based degrees of freedom. This optimization method will allow patients to be simultaneously planned for dosimetric quality and delivery efficiency without switching between delivery techniques. Example phantom and clinical cases suggest that the conversion of only three VMAT segments to modulated beams may result in a good combination of quality and efficiency.

  3. automatic arc welding: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    control computer, has been accomplished. n.n. 2 Double-Sided Arc Welding Increases Weld Joint Penetration CiteSeer Summary: this paper proposes increasing the penetration by...

  4. arc discharge lamp: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TR, were determined. It was found that there is no local LTE in this arc discharge air plasma during its spacetime evolution, and effects of strong non-izothermality have a...

  5. Kernels for Feedback Arc Set In Tournaments Stephane Bessy

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Kernels for Feedback Arc Set In Tournaments St´ephane Bessy Fedor V. Fomin Serge Gaspers Christophe´e de Montpellier 2, CNRS, 161 rue Ada, 34392 Montpellier, France. {bessy

  6. arc heater production: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the use of this type of product in order to reduce climate emissions. Key words: heat pump water heater, natural refrigerant, CO2, COP 1. unknown authors 35 Circular-Arc...

  7. arc plasma method: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for two types of plasma sources used cathodic-arc plasma source show the coupling efficiency of the plasma flow from the source to the drift Gilson, Erik 8 Computational study...

  8. Role of substrate temperature at graphene synthesis in arc discharge

    E-Print Network [OSTI]

    Fang, Xiuqi; Keidar, Michael

    2015-01-01T23:59:59.000Z

    Substrate temperature required for synthesis of graphene in arc discharge plasma was studied. It was shown that increase of the copper substrate temperature up to melting point leads to increase in the amount of graphene production and quality of graphene sheets. Favorable range of substrate temperatures for arc-based graphene synthesis was determined in relatively narrow range of about 1340-1360K which is near the melting point of copper.

  9. Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded Arcing Signatures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12ArahArc

  10. Recycling of electric-arc-furnace dust

    SciTech Connect (OSTI)

    Sresty, G.C.

    1990-05-01T23:59:59.000Z

    Electric arc furnace (EAF) dust is one of the largest solid waste streams produced by steel mills, and is classified as a waste under the Resource Conservation and Recovery Act (RCRA) by the U.S. Environmental Protection Agency (EPA). Successful recycle of the valuable metals (iron, zinc, and lead) present in the dust will result in resource conservation while simultaneously reducing the disposal problems. Technical feasibility of a novel recycling method based on using hydrogen as the reductant was established under this project through laboratory experiments. Sponge iron produced was low in zinc, cadmium, and lead to permit its recycle, and nontoxic to permit its safe disposal as an alternative to recycling. Zinc oxide was analyzed to contain 50% to 58% zinc by weight, and can be marketed for recovering zinc and lead. A prototype system was designed to process 2.5 tons per day (600 tons/year) of EAF dust, and a preliminary economic analysis was conducted. The cost of processing dust by this recycling method was estimated to be comparable to or lower than existing methods, even at such low capacities.

  11. Lightning Induced Arcing an LDRD Report

    SciTech Connect (OSTI)

    JORGENSON,ROY E.; WARNE,LARRY K.; KUNHARDT,ERICH E.

    2000-12-01T23:59:59.000Z

    The purpose of this research was to develop a science-based understanding of the early-time behavior of electric surface arcing in air at atmospheric pressure. As a first step towards accomplishing this, we used a kinetic approach to model an electron swarm as it evolved in a neutral gas under the influence of an applied electric field. A computer code was written in which pseudo-particles, each representing some number of electrons, were accelerated by an electric field. The electric field due to the charged particles was calculated efficiently using a tree algorithm. Collision of the electrons with the background gas led to the creation of new particles through the processes of ionization and photoionization. These processes were accounted for using measured cross-section data and Monte Carlo methods. A dielectric half-space was modeled by imaging the charges in its surface. Secondary electron emission from the surface, resulting in surface charging, was also calculated. Simulation results show the characteristics of a streamer in three dimensions. A numerical instability was encountered before the streamer matured to form branching.

  12. ARCS Additional FirstYear PhD Student Award The Atlanta chapter of ARCS has just informed me that they will honor us with another graduate student

    E-Print Network [OSTI]

    Arnold, Jonathan

    ARCS Additional FirstYear PhD Student Award The Atlanta chapter of ARCS has just informed me meets their definition listed above. Sincerely, Harry A. Dailey, Ph.D. Professor and Director

  13. ARC Collaborative Research Seminar Series Winter 2008

    E-Print Network [OSTI]

    Papalambros, Panos

    ) University of Michigan, Lurie Engineering Center, Level 4, GM Room Presenting: Thrust Area 1 ­ Dynamics of wheels on soft soil, ice, and hard surfaces. Real-Time Adaptive Volterra Filter Characterization of MR

  14. Arcing fault in sub-distribution branch circuits

    SciTech Connect (OSTI)

    Parise, G.; Grasseli, U.; Luozzo, V. Di (Univ. di Roma, Rome (Italy). Dept. di Ingegneria Elettrica)

    1993-04-01T23:59:59.000Z

    It's well known the importance of short-circuit current evaluation for the design of any power system. Every system is subject to faults, moreover short-circuits and ground faults can be expected in any point. Even if the maximum and minimum values are generally defined with reference at a bolted-fault, bolted short-circuits are rare and the fault usually involves arcing and burning; particularly the limit value of minimum short-circuit depends really on arcing-fault. In earlier experimental investigations into the functional simulation of insulation loss, in branch circuit conductors, the authors chose to normalize the arcing-fault simulation to be used in laboratory tests. This conventional simulation allows characterization of this intrinsically random phenomenon by means of a probabilistic approach, in order to define in statistical terms the expected short circuit value. The authors examine more closely the arcing-fault in the design of sub distribution branch-circuits as weak points of the installation. In fact, what they propose are straightforward criteria, whether in the structure of the system or in the coordination of protection, which afford a more rational control on arcing-fault.

  15. Graphite electrode arc melter demonstration Phase 2 test results

    SciTech Connect (OSTI)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; O`Connor, W.K.; Oden, L.L.; Turner, P.C.

    1996-06-01T23:59:59.000Z

    Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

  16. High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc

    E-Print Network [OSTI]

    Anders, Georgy, Yu. Yushkov, Andre

    2008-01-01T23:59:59.000Z

    emitted by dc arcs in a vacuum ambient," J. Appl. Phys. ,Plasma properties of a metal vacuum arc. II. ” Sov. Phys.1977. [4] I. G. Brown, “Vacuum arc ion sources”, Rev. Sci.

  17. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, D.E.; Lee, S.G.

    1996-08-06T23:59:59.000Z

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

  18. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, David E. (Concord, MA); Lee, Steven G. (Ann Arbor, MI)

    1996-01-01T23:59:59.000Z

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  19. Parallel vacuum arc discharge with microhollow array dielectric and anode

    SciTech Connect (OSTI)

    Feng, Jinghua; Zhou, Lin; Fu, Yuecheng; Zhang, Jianhua; Xu, Rongkun; Chen, Faxin; Li, Linbo; Meng, Shijian, E-mail: mengshijian04@126.com [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

    2014-07-15T23:59:59.000Z

    An electrode configuration with microhollow array dielectric and anode was developed to obtain parallel vacuum arc discharge. Compared with the conventional electrodes, more than 10 parallel microhollow discharges were ignited for the new configuration, which increased the discharge area significantly and made the cathode eroded more uniformly. The vacuum discharge channel number could be increased effectively by decreasing the distances between holes or increasing the arc current. Experimental results revealed that plasmas ejected from the adjacent hollow and the relatively high arc voltage were two key factors leading to the parallel discharge. The characteristics of plasmas in the microhollow were investigated as well. The spectral line intensity and electron density of plasmas in microhollow increased obviously with the decease of the microhollow diameter.

  20. Darwin : The Third DOE ARM TWP ARCS Site /

    SciTech Connect (OSTI)

    Clements, William E.; Jones, L. A. (Larry A.); Baldwin, T. (Tony); Nitschke, K. (Kim)

    2002-01-01T23:59:59.000Z

    The United States Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) Program began operations in its Tropical Western Pacific (TWP) locale in October 1996 when the first Atmospheric Radiation and Cloud Station (ARCS) began collecting data on Manus Island in Papua New Guinea (PNG). Two years later, in November 1998, a second ARCS began operations on the island of Nauru in the Central Pacific. Now a third ARCS has begun collecting data in Darwin, Australia. The Manus, Nauru, and Darwin sites are operated through collaborative agreements with the PNG National Weather Service, The Nauru Department of Industry and Economic Development (IED), and the Australian Bureau of Meteorology's (BOM) Special Services Unit (SSU) respectively. All ARM TWP activities in the region are coordinated with the South Pacific Regional Environment Programme (SPREP) based in Apia, Samoa. The Darwin ARM site and its role in the ARM TWP Program are discussed.

  1. Multi-cathode metal vapor arc ion source

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805)

    1988-01-01T23:59:59.000Z

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. One embodiment of the appaatus utilizes a multi-cathode arrangement for interaction with the anode.

  2. Graphite electrode DC arc furnace. Innovative technology summary report

    SciTech Connect (OSTI)

    NONE

    1999-05-01T23:59:59.000Z

    The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of feed composition variations on process operating conditions and slag product performance; and collecting mass balance and operating data to support equipment and instrument design.

  3. Thermocapillary and arc phenomena in stainless steel welds

    SciTech Connect (OSTI)

    Pierce, S.W.

    1993-10-01T23:59:59.000Z

    Goal was to study effect of power level and distribution on thermocapiilary-induced weld shape and of arc factors on weld shape. Thermocapillarity was apparent in both conduction mode EB welds and GTA welds, particularly in the former. A non-Gaussian arc distribution is suggested for accounting for the differences between the twoss processes. At higher current levels (200--300 A), plasma shear force also contributes to weld shape development. Evidence suggests that thermocapillary flow reversal is not a factor in normal GTA welds; EDB flow reversal occurs only at high power density levels where the keyhole mode is present.

  4. E-Print Network 3.0 - arc plasma deposition Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    deposition of TiN coatings to increase... was built at FCIPT for studying SpacecraftSolar panel - Plasma' interactions that can lead to arcing... which lead to arcing. The...

  5. Characterization of argon arc source in the infrared J. M. Bridges and A. L. Migdall

    E-Print Network [OSTI]

    Migdall, Alan

    metrologia Characterization of argon arc source in the infrared J. M. Bridges and A. L. Migdall path. Although a resistor of 0,25 is used for ignition, the arc requires no ballast during Metrologia

  6. Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma

    SciTech Connect (OSTI)

    Ribic, B.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Burgardt, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2011-04-15T23:59:59.000Z

    During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.

  7. E-Print Network 3.0 - arc plasma melting Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    UPDATE A newsletter from the Summary: was built at FCIPT for studying SpacecraftSolar panel - Plasma' interactions that can lead to arcing... which lead to arcing. The range of...

  8. E-Print Network 3.0 - assisted plasma arc Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    assisted manufacturing and to look... was built at FCIPT for studying SpacecraftSolar panel - Plasma' interactions that can lead to arcing... which lead to arcing. The range of...

  9. Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1 J. Liang,1 E aurora ­ the longitudinally propagating arc wave (LPAW) ­ associated with flapping oscillations, and K. H. Glassmeier (2009), Longitudinally propagating arc wave in the pre-onset optical aurora

  10. Control Engineering Practice 11 (2003) 14011411 Modeling and control of quasi-keyhole arc welding process

    E-Print Network [OSTI]

    Zhang, YuMing

    Control Engineering Practice 11 (2003) 1401­1411 Modeling and control of quasi-keyhole arc welding to operate the keyhole arc welding process. Because the method's effectiveness depends on the amperage reserved. Keywords: Modeling; Predictive control; Manufacturing; Welding 1. Introduction Keyhole arc

  11. ~.,Slag-Metal Equilibrium During Submerged e-~~ Arc Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ~~ . ~.·,Slag-Metal Equilibrium During Submerged ·e-~~ Arc Welding C. S. CHAI AND T. W. EAGAR A thermodynamic model of the equilibria existing between the slag and the weld metal during submerged arc welding over forty years ago, submerged arc welding has developed into one of the most efficient, most reliable

  12. Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 1 - Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding Olivier dimensional finite element model has been developed to simulate weld bead formation in multi pass hybrid laser/gas metal arc welding. The model considers both a gas metal arc welding (GMAW) electrode and a laser beam

  13. Individualization of textural and reactional microdomains in eclogites from the Bergen Arcs (Norway): Consequences for

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Individualization of textural and reactional microdomains in eclogites from the Bergen Arcs (Norway in Caledonian eclogites from the Linda°s Nappe, Bergen Arcs, Norway, in order to investigate processes in eclogites from the Bergen Arcs (Norway): Consequences for Rb/Sr and Ar/Ar radiochronometer behavior during

  14. Characteristics of a stable arc based on FAST and MIRACLE observations

    E-Print Network [OSTI]

    Boyer, Edmond

    , which contains all-sky cameras, coherent radars (STARE), and magnetometers. Both FAST and STARE observe of the arc, which is a typical signature for an evening-sector arc. The ®eld-aligned current deter- mined of small undulations associated with the arc using the all-sky cameras gives a velocity of about 2 km

  15. Heat and Metal Transfer in Gas Metal Arc Welding Using Argon and Helium

    E-Print Network [OSTI]

    Eagar, Thomas W.

    Heat and Metal Transfer in Gas Metal Arc Welding Using Argon and Helium P.G. JONSSON, T.W. EAGAR transfer in gas metal arc welding (GMAW) of mild steel using argon and helium shielding gases. Major dif properties. Various findings from the study include that an arc cannot be stru~k in a pure helium atmosphere

  16. ACYCLIC GROUPS AND WILD ARCS A. J. BERRICK AND YAN-LOI WONG

    E-Print Network [OSTI]

    Berrick, A J.

    ACYCLIC GROUPS AND WILD ARCS A. J. BERRICK AND YAN-LOI WONG Abstract. We discuss two classes, and is shown to include a number of wild arc groups in the literature. 0. Introduction This paper introduces cyclic cover of X \\ is the complement of a wild arc in S3 with the following properties. (i) S3

  17. Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 49

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 49 CESAM-OPJ-GIS Document current as of March 28, 2012 10:27 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 49 CESAM

  18. Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 50

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 50 CESAM-OPJ-GIS Document current as of June 27, 2012 10:09 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 50 CESAM

  19. Seminar (Winter '10) 16th ARC Conference Events Archive ARC Collaborative Research Seminar Series

    E-Print Network [OSTI]

    Papalambros, Panos

    Debevec, PhD We will present our work in building virtual humans at the ICT. We will cover new technology with preliminary validation and validation plans. Dynamic tire model for real-time human-in-the-loop driving we are developing to create life-like animations that can be controlled dynamically by an artificial

  20. Pulse thermal processing of functional materials using directed plasma arc

    DOE Patents [OSTI]

    Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)

    2007-05-22T23:59:59.000Z

    A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

  1. arc box test: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    arc box test First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 WHITE BOX TESTING TECHNIQUE CiteSeer...

  2. Self-organisation Processes In The Carbon ARC For Nanosynthis

    SciTech Connect (OSTI)

    Ng, Jonathan; Raitses, Yevgeny

    2014-02-26T23:59:59.000Z

    The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

  3. Self-organisation Processes In The Carbon ARC For Nanosynthis

    SciTech Connect (OSTI)

    Ng, J.; Raitses, Yefgeny [Princeton Plasma Physics Lab., Princeton, NJ (United States)

    2014-02-02T23:59:59.000Z

    The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

  4. A Generic Arc-Consistency Algorithm and its Specializations1

    E-Print Network [OSTI]

    Deville, Yves

    not take into account the semantics of constraints. In this paper, we present a new generic arc satisfaction problems (CSP). A CSP is de ned by a nite set of variables taking values from nite domains of applications include graph-coloring, warehouse locations, car-sequencing and cutting stock (see for instance 4

  5. A Generic ArcConsistency Algorithm and its Specializations 1

    E-Print Network [OSTI]

    Deville, Yves

    , these algorithms do not take into account the semantics of constraints. In this paper, we present a new generic arc as constraint satisfaction problems (CSP). A CSP is defined by a finite set of variables taking values from. Examples of applications include graph­coloring, warehouse locations, car­sequencing and cutting stock (see

  6. Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical Intra-oceanic Arc1

    E-Print Network [OSTI]

    Stern, Robert J.

    Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical at Dallas, Box 830688, Richardson, TX 75083-0688, USA A B S T R A C T Major element compositions of glass of these lavas reflects accumulation of plagioclase. Glass inclusions also show the common occurrence of felsic

  7. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 50, NO. 3, JUNE 2001 697 Robust Sensing of Arc Length

    E-Print Network [OSTI]

    Zhang, YuMing

    the distribution of the arc energy and thus the heat input and width of the weld. This work aims at improving research and equipment development. The gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW tungsten arc welding (GTAW) with argon shield. To this end, effects of welding parame- ters on spectral

  8. The use of RapidArc volumetric-modulated arc therapy to deliver stereotactic radiosurgery and stereotactic body radiotherapy to intracranial and extracranial targets

    SciTech Connect (OSTI)

    Roa, Dante E., E-mail: droa@uci.edu [Department of Radiation Oncology, Chao Family Comprehensive Cancer Center, University of California, Irvine-Medical Center, Orange, CA (United States); Schiffner, Daniel C.; Zhang Juying; Dietrich, Salam N.; Kuo, Jeffrey V.; Wong, Jason; Ramsinghani, Nilam S.; Al-Ghazi, Muthana S.A.L. [Department of Radiation Oncology, Chao Family Comprehensive Cancer Center, University of California, Irvine-Medical Center, Orange, CA (United States)

    2012-10-01T23:59:59.000Z

    Twenty-three targets in 16 patients treated with stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT) were analyzed in terms of dosimetric homogeneity, target conformity, organ-at-risk (OAR) sparing, monitor unit (MU) usage, and beam-on time per fraction using RapidArc volumetric-modulated arc therapy (VMAT) vs. multifield sliding-window intensity-modulated radiation therapy (IMRT). Patients underwent computed tomography simulation with site-specific immobilization. Magnetic resonance imaging fusion and optical tracking were incorporated as clinically indicated. Treatment planning was performed using Eclipse v8.6 to generate sliding-window IMRT and 1-arc and 2-arc RapidArc plans. Dosimetric parameters used for target analysis were RTOG conformity index (CI{sub RTOG}), homogeneity index (HI{sub RTOG}), inverse Paddick Conformity Index (PCI), D{sub mean} and D5-D95. OAR sparing was analyzed in terms of D{sub max} and D{sub mean}. Treatment delivery was evaluated based on measured beam-on times delivered on a Varian Trilogy linear accelerator and recorded MU values. Dosimetric conformity, homogeneity, and OAR sparing were comparable between IMRT, 1-arc RapidArc and 2-arc RapidArc plans. Mean beam-on times {+-} SD for IMRT and 1-arc and 2-arc treatments were 10.5 {+-} 7.3, 2.6 {+-} 1.6, and 3.0 {+-} 1.1 minutes, respectively. Mean MUs were 3041, 1774, and 1676 for IMRT, 1-, and 2-arc plans, respectively. Although dosimetric conformity, homogeneity, and OAR sparing were similar between these techniques, SRS and SBRT fractions treated with RapidArc were delivered with substantially less beam-on time and fewer MUs than IMRT. The rapid delivery of SRS and SBRT with RapidArc improved workflow on the linac with these otherwise time-consuming treatments and limited the potential for intrafraction organ and patient motion, which can cause significant dosimetric errors. These clinically important advantages make image-guided RapidArc useful in the delivery of SRS and SBRT to intracranial and extracranial targets.

  9. MAGENCO: A map generalization controller for Arc/Info

    SciTech Connect (OSTI)

    Ganter, J.H.; Cashwell, J.W.

    1994-06-01T23:59:59.000Z

    The Arc/Info GENERALIZE command implements the Douglas-Peucker algorithm, a well-regarded approach that preserves line ``character`` while reducing the number of points according to a tolerance parameter supplied by the user. The authors have developed an Arc Macro Language (AML) interface called MAGENCO that allows the user to browse workspaces, select a coverage, extract a sample from this coverage, then apply various tolerances to the sample. The results are shown in multiple display windows that are arranged around the original sample for quick visual comparison. The user may then return to the whole coverage and apply the chosen tolerance. They analyze the ergonomics of line simplification, explain the design (which includes an animated demonstration of the Douglas-Peucker algorithm), and discuss key points of the MAGENCO implementation.

  10. Comparative Analysis of Carbon Plasma in Arc and RF Reactors

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z. ['Vinca' Institute of Nuclear Sciences, P.O.B. 522, 11001 Belgrade (Serbia and Montenegro); Mohai, I.; Szepvolgyi, J. [Research Laboratory of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences H-1525 Budapest, POB 17 (Hungary)

    2004-12-01T23:59:59.000Z

    Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

  11. Plasma arc melting of titanium-tantalum alloys

    SciTech Connect (OSTI)

    Dunn, P.; Patterson, R.A. [Los Alamos National Lab., NM (United States); Haun, R. [Retech, Inc., Ukiah, CA (United States)

    1994-08-01T23:59:59.000Z

    Los Alamos has several applications for high temperature, oxidation and liquid-metal corrosion resistant materials. Further, materials property constraints are dictated by a requirement to maintain low density; e.g., less than the density of stainless steel. Liquid metal compatibility and density requirements have driven the research toward the Ti-Ta system with an upper bound of 60 wt% Ta-40 wt% Ti. Initial melting of these materials was performed in a small button arc melter with several hundred grams of material; however, ingot quantities were soon needed. But, refractory metal alloys whose constituents possess very dissimilar densities, melting temperatures and vapor pressures pose significant difficulty and require specialized melting practices. The Ti-Ta alloys fall into this category with the density of tantalum 16.5 g/cc and that of titanium 4.5 g/cc. Melting is further complicated by the high melting point of Ta(3020 C) and the relatively low boiling point of Ti(3287 C). Previous electron beam melting experience with these materials resulted, in extensive vaporization of the titanium and poor chemical homogeneity. Vacuum arc remelting(VAR) was considered as a melting candidate and discarded due to density and vapor pressure issues associated with electron beam. Plasma arc melting offered the ability to supply a cover gas to deal with vapor pressure issues as well as solidification control to help with macrosegregation in the melt and has successfully produced high quality ingots of the Ti-Ta alloys.

  12. Vacuum Arc Ion Sources: Recent Developments and Applications

    SciTech Connect (OSTI)

    Brown, Ian; Oks, Efim

    2005-05-01T23:59:59.000Z

    The vacuum arc ion source has evolved over the past twenty years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface modification. Another important use is for injection of high current beams of heavy metal ions into the front ends of particle accelerators, and much excellent work has been carried out in recent years in optimizing the source for reliable accelerator application. The source also provides a valuable tool for the investigation of the fundamental plasma physics of vacuum arc plasma discharges. As the use of the source has grown and diversified, at the same time the ion source performance and operational characteristics have been improved in a variety of different ways also. Here we review the growth and status of vacuum arc ion sources around the world, and summarize some of the applications for which the sources have been used.

  13. A Glove Box Enclosed Gas-Tungsten Arc Welding System

    SciTech Connect (OSTI)

    Reevr, E, M; Robino, C.V.

    1999-07-01T23:59:59.000Z

    This report describes an inert atmosphere enclosed gas-tungsten arc welding system which has been assembled in support of the MC2730, MC2730A and MC 3500 Radioisotope Thermoelectric Generator (RTG) Enhanced Surveillance Program. One goal of this program is to fabricate welds with microstructures and impurity levels which are similar to production heat source welds previously produced at Los Alamos National Laboratory and the Mound Facility. These welds will subsequently be used for high temperature creep testing as part of the overall component lifetime assessment. In order to maximize the utility of the welding system, means for local control of the arc atmosphere have been incorporated and a wide range of welding environments can easily be evaluated. The gas-tungsten arc welding system used in the assembly is computer controlled, includes two-axis and rotary motion, and can be operated in either continuous or pulsed modes. The system can therefore be used for detailed research studies of welding impurity effects, development of prototype weld schedules, or to mimic a significant range of production-like welding conditions. Fixturing for fabrication of high temperature creep test samples have been designed and constructed, and weld schedules for grip-tab and test welds have been developed. The microstructure of these welds have been evaluated and are consistent with those used during RTG production.

  14. Radiation in molecular dynamic simulations

    SciTech Connect (OSTI)

    Glosli, J; Graziani, F; More, R; Murillo, M; Streitz, F; Surh, M

    2008-10-13T23:59:59.000Z

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The new technique passes a key test: it relaxes to a blackbody spectrum for a plasma in local thermodynamic equilibrium. This new tool also provides a method for assessing the accuracy of energy and momentum exchange models in hot dense plasmas. As an example, we simulate the evolution of non-equilibrium electron, ion, and radiation temperatures for a hydrogen plasma using the new molecular dynamics simulation capability.

  15. Structure and seismic stratigraphy of the Bonin Trench-Arc system

    E-Print Network [OSTI]

    Bandy, William Lee

    1982-01-01T23:59:59.000Z

    . An oblique collision between Japan and the Bonin Arc during the opening of the Japan Sea both compressed the arc and induced a clockwise torque along the northern margin of the arc which bent and fractured the arc, forming the en-echelon structures.... Cartoon illustrating three possible mechanisms for faulting and subsidence of the inner trench slope 108 Fig. 47. Development history of the forearc region of the Japan System off northern Honshu 112 Fig. 48. Trends of the en-echelon features...

  16. Formation of metal oxides by cathodic arc deposition

    SciTech Connect (OSTI)

    Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.

    1995-03-01T23:59:59.000Z

    Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.

  17. A dimensionless parameter model for arc welding processes

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    1994-12-31T23:59:59.000Z

    A dimensionless parameter model previously developed for C0{sub 2} laser beam welding has been shown to be applicable to GTAW and PAW autogenous arc welding processes. The model facilitates estimates of weld size, power, and speed based on knowledge of the material`s thermal properties. The dimensionless parameters can also be used to estimate the melting efficiency, which eases development of weld schedules with lower heat input to the weldment. The mathematical relationship between the dimensionless parameters in the model has been shown to be dependent on the heat flow geometry in the weldment.

  18. Advanced RenewableEnergy Company ARC Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat 1AMEE Jump to:Ohio:Ads-tec GmbHRenewableEnergy Company ARC

  19. Arc Vault Significantly Reduces Electrical Hazards | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12ArahArc Vault

  20. ARCS - Access Rate Control System - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral20ALSNewstt^APPLIANCE STANDARDS HowARCS

  1. Waste form development for a DC arc furnace

    SciTech Connect (OSTI)

    Feng, X.; Bloomer, P.E.; Chantaraprachoom, N.; Gong, M.; Lamar, D.A.

    1996-09-01T23:59:59.000Z

    A laboratory crucible study was conducted to develop waste forms to treat nonradioactive simulated {sup 238}Pu heterogeneous debris waste from Savannah River, metal waste from the Idaho National Engineering Laboratory (INEL), and nominal waste also from INEL using DC arc melting. The preliminary results showed that the different waste form compositions had vastly different responses for each processing effect. The reducing condition of DC arc melting had no significant effects on the durability of some waste forms while it decreased the waste form durability from 300 to 700% for other waste forms, which resulted in the failure of some TCLP tests. The right formulations of waste can benefit from devitrification and showed an increase in durability by 40%. Some formulations showed no devitrification effects while others decreased durability by 200%. Increased waste loading also affected waste form behavior, decreasing durability for one waste, increasing durability by 240% for another, and showing no effect for the third waste. All of these responses to the processing and composition variations were dictated by the fundamental glass chemistry and can be adjusted to achieve maximal waste loading, acceptable durability, and desired processing characteristics if each waste formulation is designed for the result according to the glass chemistry.

  2. Thermal Treatment of Solid Wastes Using the Electric Arc Furnace

    SciTech Connect (OSTI)

    O'Connor, W.K.; Turner, P.C.

    1999-09-01T23:59:59.000Z

    A thermal waste treatment facility has been developed at the Albany Research Center (ARC) over the past seven years to process a wide range of heterogeneous mixed wastes, on a scale of 227 to 907 kg/h (500 to 2,000 lb/h). The current system includes a continuous feed system, a 3-phase AC, 0.8 MW graphite electrode arc furnace, and a dedicated air pollution control system (APCS) which includes a close-coupled thermal oxidizer, spray cooler, baghouse, and wet scrubber. The versatility of the complete system has been demonstrated during 5 continuous melting campaigns, ranging from 11 to 25 mt (12 to 28 st) of treated wastes per campaign, which were conducted on waste materials such as (a) municipal incinerator ash, (b) simulated low-level radioactive, high combustible-bearing mixed wastes, (c) simulated low-level radioactive liquid tank wastes, (d) heavy metal contaminated soils, and (e) organic-contaminated dredging spoils. In all cases, the glass or slag products readily passed the U.S. Environmental Protection Agency (EPA) Toxicity Characteristic Leachability Program (TCLP) test. Additional studies are currently under way on electric utility wastes, steel and aluminum industry wastes, as well as zinc smelter residues. Thermal treatment of these solid waste streams is intended to produce a metallic product along with nonhazardous glass or slag products.

  3. Neutral beam dump with cathodic arc titanium gettering

    SciTech Connect (OSTI)

    Smirnov, A.; Korepanov, S. A.; Putvinski, S. [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States); Krivenko, A. S.; Murakhtin, S. V.; Savkin, V. Ya. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2011-03-15T23:59:59.000Z

    An incomplete neutral beam capture can degrade the plasma performance in neutral beam driven plasma machines. The beam dumps mitigating the shine-through beam recycling must entrap and retain large particle loads while maintaining the beam-exposed surfaces clean of the residual impurities. The cathodic arc gettering, which provides high evaporation rate coupled with a fast time response, is a powerful and versatile technique for depositing clean getter films in vacuum. A compact neutral beam dump utilizing the titanium arc gettering was developed for a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams. The titanium evaporator features a new improved design. The beam dump is capable of handling large pulsed gas loads, has a high sorption capacity, and is robust and reliable. With the beam particle flux density of 5 x 10{sup 17} H/(cm{sup 2}s) sustained for 3-10 ms, the beam recycling coefficient, defined as twice the ratio of the hydrogen molecular flux leaving the beam dump to the incident flux of high-energy neutral atoms, is {approx}0.7. The use of the beam dump allows us to significantly reduce the recycling of the shine-through neutral beam as well as to improve the vacuum conditions in the machine.

  4. Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc

    E-Print Network [OSTI]

    O'Toole, Alice J.

    Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein processes. Infusions of the -adrenoreceptor agonist, clen- buterol, into the BLA immediately after training increased Arc protein levels in the dorsal hippocampus. Additionally, posttraining intra-BLA infusions

  5. Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding sources for finite element simulation of gas metal arc welding (GMAW). Design for the modeling of metal deposition results in a direct calculation of the formation of the weld bead, without any

  6. ~DELING OF METAL TRANSFKR IN GAS METAL ARC WELDING Yong -Seog Kim and T. W. Eagar

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) ) ~DELING OF METAL TRANSFKR IN GAS METAL ARC WELDING Yong -Seog Kim and T. W. Eagar theory and the pinch i ns t a bility theor y as a function of welding cur rent . Experimental of the gas metal arc process in the late 1940s, it has become one of the most important welding processes

  7. A COUPLED APPROACH FOR THE MODELLING OF ARC WELDING Christel Pequet1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A COUPLED APPROACH FOR THE MODELLING OF ARC WELDING PROCESSES Christel Pequet1 , Patrice Lasne1 ; email : michel.bellet@ensmp.fr Keywords: welding, finite elements, thermal arising in arc welding as well as their interaction: heat input, metal deposit, solidification, phase

  8. Oxygen and Nitroaen Contamination During Submerged Arc Wel ding of Titanium

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) ) ··- -~ Oxygen and Nitroaen Contamination During Submerged Arc Wel ding of Titanium T· \\v the costs of submerged arc welding of titanium. In general it i s found that the cost of titanium submerged welding of titani um. The advantages and disadvantages of flux shielded weldinq of titanium are outlined

  9. Assimilation of Ultramafic Rock in Subduction-Related Magmatic Arcs Author(s): Peter B. Kelemen

    E-Print Network [OSTI]

    Assimilation of Ultramafic Rock in Subduction-Related Magmatic Arcs Author(s): Peter B. Kelemen Source: The Journal of Geology, Vol. 94, No. 6 (Nov., 1986), pp. 829-843 Published by: The University. http://www.jstor.org #12;ASSIMILATION OF ULTRAMAFIC ROCK IN SUBDUCTION-RELATED MAGMATIC ARCS1 PETER B

  10. Small and mesoscale properties of a substorm onset auroral arc H. U. Frey,1

    E-Print Network [OSTI]

    Bergen, Universitetet i

    Small and mesoscale properties of a substorm onset auroral arc H. U. Frey,1 O. Amm,2 C. C. Chaston; revised 22 June 2010; accepted 28 June 2010; published 7 October 2010. [1] We present small and mesoscale. Good agreement could be reached for the mesoscale arc properties. A qualitative analysis

  11. Method and device for reducing overpenetration at the start of plasma arc welds

    DOE Patents [OSTI]

    Sanders, John M. (Jackson Township, Stark County, OH); Lehmann, John M. (Bedford County, VA); Ryan, Patrick M. (Washington Township, Stark County, OH)

    1998-01-01T23:59:59.000Z

    A shim for improving plasma arc weld quality has ends tapered at about 25.degree. and notches at each end roughly centered over the corner between the tapered ends and main body of the shim. The improved shim allows lower starting plasma arc heat input and reduces the occurrence of sagging, or overpenetration, of the weld.

  12. Effect of hydrogen in an argon GTAW shielding gas: Arc characteristics and bead morphology

    SciTech Connect (OSTI)

    Onsoeien, M.; Olson, D.L.; Liu, S. (Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research); Peters, R. (Delft Technological Univ. (Netherlands))

    1995-01-01T23:59:59.000Z

    The influence of hydrogen additions to an argon shielding gas on the heat input and weld bead morphology was investigated using the gas tungsten arc welding process. Variations in weld bead size and shape with hydrogen additions were related to changes in the ability of the arc to generate heat and not to generate perturbations in the weld pool caused by Marangoni fluid flow.

  13. Electrical Circuit Flashover Model of Polluted Insulators under AC Voltage Based on the Arc Root Voltage Gradient Criterion

    E-Print Network [OSTI]

    Yang, Qing

    In order to study the flashover mechanism of polluted insulators under AC voltage, a new arc propagation criterion which is based on an arc root voltage gradient is proposed. This criterion can explain the variation of the ...

  14. Study of JET Soft Housekeeping Waste Volume Reduction by Plasma Arc Centrifuge and Gasification in Countercurrent Regime Methods

    E-Print Network [OSTI]

    Study of JET Soft Housekeeping Waste Volume Reduction by Plasma Arc Centrifuge and Gasification in Countercurrent Regime Methods

  15. Welding : arc-welded joints in aluminium and its alloys : quality levels for imperfections : technical corrigendum 1

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2006-01-01T23:59:59.000Z

    Welding : arc-welded joints in aluminium and its alloys : quality levels for imperfections : technical corrigendum 1

  16. Oxidation behavior of arc evaporated Al-Cr-Si-N thin films

    SciTech Connect (OSTI)

    Tritremmel, Christian; Daniel, Rostislav; Mitterer, Christian; Mayrhofer, Paul H.; Lechthaler, Markus; Polcik, Peter [Christian Doppler Laboratory for Advanced Hard Coatings, Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Christian Doppler Laboratory for Application Oriented Coating Development, Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); OC Oerlikon Balzers AG, Iramali 18, LI-9496 Balzers (Liechtenstein); PLANSEE Composite Materials GmbH, Siebenbuergerstrasse 23, D-86983 Lechbruck am See (Germany)

    2012-11-15T23:59:59.000Z

    The impact of Al and Si on the oxidation behavior of Al-Cr-(Si)-N thin films synthesized by arc evaporation of powder metallurgically prepared Al{sub x}Cr{sub 1-x} targets with x = Al/(Al + Cr) of 0.5, 0.6, and 0.7 and (Al{sub 0.5}Cr{sub 0.5}){sub 1-z}Si{sub z} targets with Si contents of z = 0.05, 0.1, and 0.2 in N{sub 2} atmosphere was studied in detail by means of differential scanning calorimetry, thermogravimetric analysis (TGA), x-ray diffraction, and Raman spectroscopy. Dynamical measurements in synthetic air (up to 1440 Degree-Sign C) revealed the highest onset temperature of pronounced oxidation for nitride coatings prepared from the Al{sub 0.4}Cr{sub 0.4}Si{sub 0.2} target. Isothermal TGA at 1100, 1200, 1250, and 1300 Degree-Sign C highlight the pronounced improvement of the oxidation resistance of Al{sub x}Cr{sub 1-x}N coatings by the addition of Si. The results show that Si promotes the formation of a dense coating morphology as well as a dense oxide scale when exposed to air.

  17. Phase-Space Volume of Regions of Trapped Motion: Multiple Ring Components and Arcs

    E-Print Network [OSTI]

    L. Benet; O. Merlo

    2008-10-30T23:59:59.000Z

    The phase--space volume of regions of regular or trapped motion, for bounded or scattering systems with two degrees of freedom respectively, displays universal properties. In particular, sudden reductions in the phase-space volume or gaps are observed at specific values of the parameter which tunes the dynamics; these locations are approximated by the stability resonances. The latter are defined by a resonant condition on the stability exponents of a central linearly stable periodic orbit. We show that, for more than two degrees of freedom, these resonances can be excited opening up gaps, which effectively separate and reduce the regions of trapped motion in phase space. Using the scattering approach to narrow rings and a billiard system as example, we demonstrate that this mechanism yields rings with two or more components. Arcs are also obtained, specifically when an additional (mean-motion) resonance condition is met. We obtain a complete representation of the phase-space volume occupied by the regions of trapped motion.

  18. METAL TRANSFER CONTROL IN GAS METAL ARC WELDING L.A. Jones, T.W. Eagar, J.H. Lang

    E-Print Network [OSTI]

    Eagar, Thomas W.

    METAL TRANSFER CONTROL IN GAS METAL ARC WELDING L.A. Jones, T.W. Eagar, J.H. Lang Massachusetts Institute of Technology Cambridge, MA 02139 USA Abstract Power input to the arc in gas metal arc welding to decouple these processes. Methods to achieve this decoupling are discussed. Pulsed-power welding is widely

  19. Method of operating a centrifugal plasma arc furnace

    DOE Patents [OSTI]

    Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

    1998-03-24T23:59:59.000Z

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 3}. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs.

  20. Processing electric arc furnace dust into saleable chemical products

    SciTech Connect (OSTI)

    NONE

    1998-04-01T23:59:59.000Z

    The modern steel industry uses electric arc furnace (EAF) technology to manufacture steel. A major drawback of this technology is the production of EAF dust, which is listed by the U.S. Environmental Protection Agency as a hazardous waste under the Resource Conservation and Recovery Act. The annual disposal of approximately 0.65 million tons of EAF dust in the United States and Canada is an expensive, unresolved problem for the steel industry. EAF dust byproducts are generated during the manufacturing process by a variety of mechanisms. The dust consists of various metals (e.g., zinc, lead, cadmium) that occur as vapors at 1,600{degrees}C (EAF hearth temperature); these vapors are condensed and collected in a baghouse. The production of one ton of steel will generate approximately 25 pounds of EAF dust as a byproduct, which is currently disposed of in landfills.

  1. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, Lowell D. (Kingston, TN)

    1984-01-01T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  2. Method of operating a centrifugal plasma arc furnace

    DOE Patents [OSTI]

    Kujawa, Stephan T. (Butte, MT); Battleson, Daniel M. (Butte, MT); Rademacher, Jr., Edward L. (Butte, MT); Cashell, Patrick V. (Butte, MT); Filius, Krag D. (Butte, MT); Flannery, Philip A. (Ramsey, MT); Whitworth, Clarence G. (Butte, MT)

    1998-01-01T23:59:59.000Z

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe.sub.3 O.sub.4. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe.sub.2 O.sub.3. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater.

  3. Static Heat Loads in the LHC Arc Cryostats: Final Assessment

    E-Print Network [OSTI]

    Parma, V

    2010-01-01T23:59:59.000Z

    This note presents the final assessment of the static heat loads in the LHC arc cryostats, using different experimental methods during the first commissioning period in 2007. This assessment further develops and completes previous estimates made during the commissioning of sector 7_8 [1]. The estimate of the helium inventory, a prerequisite for the heat load calculation, is also presented. Heat loads to the cold mass are evaluated from the internal energy balance during natural as well as powered warm-ups of the helium baths in different subsector. The helium inventory is calculated from the internal energy balance during powered warm-ups and matched with previous assessments. Furthermore, heat loads to the thermal shield are estimated from the non-isothermal cooling of the supercritical helium in line E. The comparison of measured heat loads with previous estimates and with budgeted values is then presented, while their correlation with some important parameters like insulation vacuum pressure and some heat ...

  4. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, L.D.

    1982-03-25T23:59:59.000Z

    The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  5. Gas-tungsten arc welding of aluminum alloys

    SciTech Connect (OSTI)

    Frye, L.D.

    1984-11-20T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one micro-inch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  6. PNNL-21407 Dynamic Processes in Biology, Chemistry, and Materials...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of days, months, and years, the molecular- and atomic-scale mechanisms, such as protein folding and electron transfer processes that influence these longer scale behaviors,...

  7. atomic scale interface: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with both trans and gauche conformations bound to the gold clusters at top, bridge and hollow bonding sites. Comparing our results with the experimental data of Hihath et al....

  8. Atomic Scale Details of Defect-Boundary Interactions

    E-Print Network [OSTI]

    Chen, Di

    2014-12-18T23:59:59.000Z

    consists of alternately positioned interstitials and vacancies. The subsequent defect annihilation between neighboring defects on the chain leads to the defect transport. We identify three types of defect transport models which involve different chains...

  9. Measurement of Transient Atomic-scale Displacements in Thin Films...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    low-a mode. The inset shows a streak camera measurement of the x-ray pulse duration. Ultrafast x-ray diffraction techniques typically utilize synchronized laser pulses as a...

  10. Exploring materials in 3D down to the atomic scale

    E-Print Network [OSTI]

    right into Viktoriastrasse and follow signs for "Hotel Allegro/Kursaal" A At Viktoriaplatz turn left into Kornhausstrasse A Hotel Allegro/Kursaal is situated on the right side of the road There is paid parking on site

  11. Atomic-scale Structural Characterizations of Functional Epitaxial Thin Films

    E-Print Network [OSTI]

    Zhu, Yuanyuan

    2013-06-03T23:59:59.000Z

    ................................................................ 10 1.3.1 Superconducting FeSe0.5Te0.5 epitaxial films........................................ 10 1.3.2 YBa2Cu3O7-x(YBCO) epitaxial thin films and flux-pinning effects ...... 14 1.3.3 Perovskite oxide epitaxial thin films... ...................................... 22 Figure 1.9. (a) Schematic illustration of ABO3 perovskite structure. (b) The corner -sharing oxygen octahedra in perovskite structure. . ................................... 23 Figure 1.10. (a) A HRTEM micrograph,67 (b) a Cs-corrected HRTEM image...

  12. Atomic-scale Structural Characterizations of Functional Epitaxial Thin Films 

    E-Print Network [OSTI]

    Zhu, Yuanyuan

    2013-06-03T23:59:59.000Z

    by computer .......................................... 157 7.3.2. Thin films and TEM samples preparation ......................................... 158 7.3.3. Cs-corrected STEM and quantitative image processing .................... 159 7.4 Results... ......................................................................................................... 28 Figure 1.13. HR-STEM micrograph of Graphene (a) before83 and (b) after84 probe CS-correction. ............................................................................................ 29 Figure 2.1. Schematic diagram of the pulsed laser...

  13. Quartz Crystal Microbalance Studies of Atomic Scale Friction Principal Investigator

    E-Print Network [OSTI]

    Krim, Jacqueline

    with chemisorbed overlayers exposed to the rubbing action of the STM tip, the goal being direct imaging of a #12 scale performed on toluene films adsorbed on atomically uniform C60, Ag(111) and mica substrates toluene. They are expected to reveal how widespread are recent theoretical observations that wetting

  14. Atomic-scale design of radiation-tolerant nanocomposites

    E-Print Network [OSTI]

    Demkowicz, Michael J.

    Recent work indicates that materials with nanoscale architectures, such as nanolayered Cu-Nb composites and nanoscale oxide dispersion-strengthened steels, are both thermally stable and offer improved performance under ...

  15. Discovery of novel hydrogen storage materials: an atomic scale...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    several key capabilities to be effective: (i) accurate prediction of decomposition thermodynamics, (ii) prediction of crystal structures for unknown hydrides, and (iii) prediction...

  16. atomic scale heating: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of a BEC in contact with its thermal cloud. Of course, other mechanisms also provide heat and also particle loss. From varied data on optically trapped cesium BEC's, we...

  17. Atomic-scale Authentication Using Resonant Tunnelling Diodes

    E-Print Network [OSTI]

    J. Roberts; I. E. Bagci; M. A. M. Zawawi; J. Sexton; N. Hulbert; Y. J. Noori; M. P. Young; C. S. Woodhead; M. Missous; M. A. Migliorato; U. Roedig; R. J. Young

    2015-02-23T23:59:59.000Z

    The rapid development of technology has provided a wealth of resources enabling the trust of everyday interactions to be undermined. Authentication schemes aim to address this challenge by providing proof of identity. This can be achieved by using devices that, when challenged, give unique but reproducible responses. At present, these distinct signatures are commonly generated by physically unclonable functions, or PUFs. These devices provide a straightforward measurement of a physical characteristic of their structure that has inherent randomness, due to imperfections in the manufacturing process. These hard-to-predict physical responses can generate a unique identity that can be used for authentication without relying on the secrecy of stored data. However, the classical design of these devices limits both their size and security. Here we show that the extensively studied problematic fluctuations in the current-voltage measurements of resonant tunnelling diodes (RTDs) provide an uncomplicated, robust measurement that can function as a PUF without conventional resource limitations. This is possible due to quantum tunnelling within the RTD, and on account of these room temperature quantum effects, we term such devices QUFs - quantum unclonable functions. As a result of the current-voltage spectra being dependent on the atomic structure and composition of the nanostructure within the RTD, each device provides a high degree of uniqueness, whilst being impossible to clone or simulate, even with state-of-the-art technology. We have thus created PUF-like devices requiring the fewest resources which make use of quantum phenomena in a highly manufacturable electronic device operating at room temperature. Conventional spectral analysis techniques, when applied to our QUFs, will enable reliable generation of unpredictable unique identities which can be employed in advanced authentication systems.

  18. atomic scale defect: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    coherent interface between topologically distinct phases of spinor Bose-Einstein condensates. Magnus O. Borgh; Janne Ruostekoski 2012-07-03 17 Visualization of Large-scale...

  19. Discovery of novel hydrogen storage materials: an atomic scale

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContract ManagementDiscovering How Muscles Really Work Discovering How

  20. Technical manual, redesigned ARC-2A automatic radon counter. Final report

    SciTech Connect (OSTI)

    Littfin, K.M.

    1992-09-01T23:59:59.000Z

    The ARC-2A Automatic Radon Counter (Serial No. 87003) was manufactured in 1987 by Ocean Communication Systems, Inc, Panama City, Florida. It was designed as a stand-alone system, but was consistently plagued with problems. The manufacturer could not repair the machine. The ARC-2A was completely redesigned at NCCOSC RDT and E Division. It is now interfaced to a computer. A new manual was written with updated information and user instructions. The ARC-2A is an integral part of ongoing electro-optic propagation studies.... Radon, Electro-optics, Aerosol.

  1. Exhaust-gas measurements from NASAs HYMETS arc jet.

    SciTech Connect (OSTI)

    Miller, Paul Albert

    2010-11-01T23:59:59.000Z

    Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.

  2. The evolution of ion charge states in cathodic vacuum arc plasmas: a review

    SciTech Connect (OSTI)

    Anders, Andre

    2011-12-18T23:59:59.000Z

    Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

  3. How do I display the Map of Wind Farms csv coordinates in ArcMap...

    Open Energy Info (EERE)

    display the Map of Wind Farms csv coordinates in ArcMap software? Home > Groups > Geospatial I downloaded the Map of Wind Farms data as a .csv from http:en.openei.orgwiki...

  4. Controlling electrode gap during vacuum arc remelting at low melting current

    DOE Patents [OSTI]

    Williamson, R.L.; Zanner, F.J.; Grose, S.M.

    1997-04-15T23:59:59.000Z

    An apparatus and method are disclosed for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived. 5 figs.

  5. Controlling electrode gap during vacuum arc remelting at low melting current

    DOE Patents [OSTI]

    Williamson, Rodney L. (Albuquerque, NM); Zanner, Frank J. (Sandia Park, NM); Grose, Stephen M. (Glenwood, WV)

    1997-01-01T23:59:59.000Z

    An apparatus and method for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived.

  6. How do I display the Map of Wind Farms csv coordinates in ArcMap...

    Open Energy Info (EERE)

    do I display the Map of Wind Farms csv coordinates in ArcMap software? Home > Groups > Geospatial I downloaded the Map of Wind Farms data as a .csv from http:en.openei.orgwiki...

  7. Innovative Energy Conservation Through Scrao Pre-heating in an Electric Arc Furnace

    E-Print Network [OSTI]

    Dicion, A.

    2013-01-01T23:59:59.000Z

    This paper will present an innovative energy conservation technology for scrap pre-heating in an Electric Arc Furnace that is being implemented in an industrial facility in Ontario. The objective of the paper is to examine the electrical...

  8. Improving the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs, and Side Vents

    Broader source: Energy.gov [DOE]

    This factsheet describes the benefits of a high-performance aluminum bronze alloy to basic oxygen furnace and electric arc furnace components such as hoods, roofs, and side vents.

  9. An Archean Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter...

    Open Energy Info (EERE)

    Felsic Dyke Swarm In A Nascent Arc- The Hunter Mine Group, Abitibi Greenstone Belt, Canada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: An...

  10. Coexistence of Fermi arcs with two-dimensional gapless Dirac states

    E-Print Network [OSTI]

    Grushin, Adolfo G.

    We present a physical scenario in which both Fermi arcs and two-dimensional gapless Dirac states coexist as boundary modes at the same two-dimensional surface. This situation is realized in topological insulator–Weyl ...

  11. Volatilization and redox testing in a DC arc melter: FY-93 and FY-94

    SciTech Connect (OSTI)

    Grandy, J.D.; Sears, J.W.; Soelberg, N.R.; Reimann, G.A.; McIlwain, M.E.

    1996-07-01T23:59:59.000Z

    The purpose of these experiments was to study the dissolution, retention, volatilization, and trapping of transuranic radionuclide elements (TRUs), mixed fission and activation products, and high vapor pressure metals (HVPMS) during processing in a high temperature arc furnace. In all cases, surrogate elements (lanthanides) were used in place of radioactive ones. The experiments were conducted utilizing a small DC arc melter developed at the Idaho National Engineering Laboratory (INEL) Research Center (IRC). The small arc melter was originally developed in 1992 and has been used previously for waste form studies of iron enriched basalt (IEB) and IEB with zirconium and titanium additions (IEB4). Section 3 contains a description of the small arc melter and its operational capabilities are discussed in Chapter 4. The remainder of the document describes each testing program and then discusses results and findings.

  12. Subduction Controls of Hf and Nd Isotopes in Lavas of the Aleutian Island Arc

    E-Print Network [OSTI]

    Yogodzinski, Gene

    2011-01-01T23:59:59.000Z

    an Experimental Study. J Petrol. 49, 717-740 Hildreth, W. ,element abundances. J Petrol. 45, 1845-1875 Jicha, B.R. ,Pacific arc-basin systems. J Petrol. 40, 1579-1611 Perfit,

  13. Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies

    Broader source: Energy.gov [DOE]

    This factsheet describes a project to develop direct steelmaking through the combination of microwave, electric arc, and exothermal heating, a process which is meant to eliminate traditional, intermediate steelmaking steps.

  14. Accelerated molecular dynamics and equation-free methods for simulating diffusion in solids.

    SciTech Connect (OSTI)

    Deng, Jie; Zimmerman, Jonathan A.; Thompson, Aidan Patrick; Brown, William Michael (Oak Ridge National Laboratories, Oak Ridge, TN); Plimpton, Steven James; Zhou, Xiao Wang; Wagner, Gregory John; Erickson, Lindsay Crowl

    2011-09-01T23:59:59.000Z

    Many of the most important and hardest-to-solve problems related to the synthesis, performance, and aging of materials involve diffusion through the material or along surfaces and interfaces. These diffusion processes are driven by motions at the atomic scale, but traditional atomistic simulation methods such as molecular dynamics are limited to very short timescales on the order of the atomic vibration period (less than a picosecond), while macroscale diffusion takes place over timescales many orders of magnitude larger. We have completed an LDRD project with the goal of developing and implementing new simulation tools to overcome this timescale problem. In particular, we have focused on two main classes of methods: accelerated molecular dynamics methods that seek to extend the timescale attainable in atomistic simulations, and so-called 'equation-free' methods that combine a fine scale atomistic description of a system with a slower, coarse scale description in order to project the system forward over long times.

  15. Low pressure arc discharge lamp apparatus with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, M.W.; George, W.A.; Maya, J.

    1987-10-06T23:59:59.000Z

    A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25 C. 3 figs.

  16. Un estudio comparativo de dos herramientas MDA: OptimalJ y ArcStyler

    E-Print Network [OSTI]

    Ortín, María José

    Un estudio comparativo de dos herramientas MDA: OptimalJ y ArcStyler J. García Molina, J. Rodríguez MDA. En esta ponencia presentamos los resultados de un trabajo que ha consistido en realizar una comparación de las dos herramientas MDA más extendidas: OptimalJ y ArcStyler. Primero evaluamos cada una de

  17. A static voltage-current characteristic for the low current DC arc

    E-Print Network [OSTI]

    Moores, Gregory Lee

    1998-01-01T23:59:59.000Z

    each flight had caused cracks in the Kapton insulation of the internal wires (Figure 3a). Eventually, through additional handling, these cracks widened enough to allow adjacent conductors to touch forming a short circuit (Figure 3b). This contact may... have been caused by vibration, a tug on the cable or some other mechanical transient because it occurred briefly. When the cable relaxed the conductors separated, drawing an arc (Figure 3c). It was the arc ignition that the astronauts heard...

  18. JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs

    SciTech Connect (OSTI)

    Bogacz, Slawomir Alex; Krafft, Geoffrey A.; Morozov, Vasiliy S.; Roblin, Yves R.

    2013-06-01T23:59:59.000Z

    We propose a demonstration experiment for a new concept of a 'dogbone' RLA with multi-pass return arcs -- JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we describe a test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected in the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The hardware requirements are not very demanding making it straightforward to implement. Such an RLA may have applications going beyond muon acceleration: in medical isotope production, radiation cancer therapy and homeland security.

  19. Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.

    SciTech Connect (OSTI)

    Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

    2012-01-01T23:59:59.000Z

    Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

  20. Statistical quality control for volumetric modulated arc therapy (VMAT) delivery using machine log data

    E-Print Network [OSTI]

    Cheong, Kwang-Ho; Kang, Sei-Kwon; Yoon, Jai-Woong; Park, Soah; Hwang, Taejin; Kim, Haeyoung; Kim, Kyoung Ju; Han, Tae Jin; Bae, Hoonsik

    2015-01-01T23:59:59.000Z

    The aim of this study is to set up statistical quality control for monitoring of volumetric modulated arc therapy (VMAT) delivery error using machine log data. Eclipse and Clinac iX linac with the RapidArc system (Varian Medical Systems, Palo Alto, USA) is used for delivery of the VMAT plan. During the delivery of the RapidArc fields, the machine determines the delivered motor units (MUs) and gantry angle position accuracy and the standard deviations of MU (sigma_MU; dosimetric error) and gantry angle (sigma_GA; geometric error) are displayed on the console monitor after completion of the RapidArc delivery. In the present study, first, the log data was analyzed to confirm its validity and usability; then, statistical process control (SPC) was applied to monitor the sigma_MU and sigma_GA in a timely manner for all RapidArc fields: a total of 195 arc fields for 99 patients. The sigma_MU and sigma_GA were determined twice for all fields, that is, first during the patient-specific plan QA and then again during th...

  1. A calorimetric-based comparison of gas tungsten and plasma arc welding processes

    SciTech Connect (OSTI)

    Knorovsky, G.A.; Fuerschbach, P.W.

    1988-01-01T23:59:59.000Z

    Measurements of arc and melting efficiencies have been made for pulsed and continuous mode Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW) processes. Welds were made on 2.5 mm total thickness pure Ni and 304 Stainless Steel in a standing edge weld geometry at constant nominal machine output settings which varied average current with travel speed. Under continuous current conditions, the measured heat input remained approximately constant for the conditions examined (250-1250 mm/min), while melting efficiency increased dramatically (0-/approximately/0.4). Arc efficiencies were relatively constant, remaining in the range of /approximately/0.75-0.85 for GTAW and somewhat less for PAW. Values of melting efficiency for Ni were slightly less than those for 304 when compared at similar travel speeds, though both tended toward the same limit (/approximately/0.4). The PAW results were not appreciably higher than the GTAW. In addition to melting efficiency the centerline depth of penetration was also measured. In contrast to the GTAW results, which increased with speed at lower travel speeds and then plateaued at 0.8 mm, the PAW results increased monotonically with speed to a maximum of 1.0 mm. In conclusion, calorimetric measurements of nonconsumable arc welding processes have been found helpful in understanding conditions under which efficient arc welds with minimal heat inputs for a desired weld penetration can be made. 10 figs.

  2. Understanding environmental leachability of electric arc furnace dust

    SciTech Connect (OSTI)

    Stegemann, J.A.; Roy, A.; Caldwell, R.J.; Schilling, P.J.; Tittsworth, R.

    2000-02-01T23:59:59.000Z

    Dust from production of steel in an electric arc furnace (EAF) contains a mixture of elements that pose a challenge for both recovery and disposal. This paper relates the leachability of six Canadian EAF dusts in four leaching tests [distilled water, Ontario Regulation 347 Leachate Extraction Procedure, Amount Available for Leaching (AALT), and pH 5 Stat] to their mineralogy. Chromium and nickel contaminants in EAF dust are largely unleachable (<5% available in AALT and pH 5 Stat), as they are found with the predominant spinel ferrite phase in EAF dust. However, even a small proportion of oxidized chromium can result in significant leachate concentrations of highly toxic chromate. The leachability of zinc (7--50% available), lead (2--17% available), and cadmium (9--55% available) can be significant, as large fractions of these contaminants are found as chlorides and oxides. The leaching of these metals is largely controlled by pH. The acid neutralization capacity of the EAF dusts appeared to be controlled by dissolution of lime and zincite, and results from regulatory leaching tests can be misleading because the variable acid neutralization capacity of EAF dusts can lead to very different final leachate pHs (5--12.4). A more informative approach would be to evaluate the total amounts of contaminants available in the long term, and the acid neutralization capacity.

  3. Recycling of electric arc furnace dust: Jorgensen steel facility

    SciTech Connect (OSTI)

    Jackson, T.W.; Chapman, J.S.

    1995-01-01T23:59:59.000Z

    This document is an evaluation of the Ek Glassification(TM) Process to recycle and convert K061-listed waste (Electric Arc Furnace or EAF dust) and other byproducts of the steel-making industry into usable products. The Process holds potential for replacing the need for expensive disposal costs associated with the listed waste with the generation of marketable products. The products include colored glass and glass-ceramics; ceramic glazes, colorants, and fillers; roofing granules and sandblasting grit; and materials for Portland cement production. Field testing of the technology was conducted by the U.S. Environmental Protection Agency (U.S. EPA) in early July of 1991 at the Earle M. Jorgensen Steel Co. (EMJ) plant in Seattle, Washington, and both technical and economic aspects of the technology were examined. TCLP testing of the product determined that leachability characteristics of metals in the product meet treatment standards for K061-listed waste. The Process was also shown to be economically viable, based on capital and operating cost estimates, and profit and revenue forecasts for a 21,000 ton-per-year operation. Although this effort showed that the technology holds promise, regulatory compliance should be evaluated on the basis of the actual hardware configuration and operating procedures along with the leachability of the specific product formulations to be used.

  4. The modelling of irradiation embrittlement in submerged-arc welds

    SciTech Connect (OSTI)

    Bolton, C.J.; Buswell, J.T.; Jones, R.B.; Moskovic, R.; Priest, R.H. [Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre

    1996-12-31T23:59:59.000Z

    Until very recently, the irradiation embrittlement behavior of submerged-arc welds has been interpreted in terms of two mechanisms, namely a matrix damage component and an additional component due to the irradiation-enhanced production of copper-rich precipitates. However, some of the weld specimens from a recent accelerated re-irradiation experiment have shown high Charpy shifts which exceeded the values expected from the measured shift in yield stress. Microstructural examination has revealed the occurrence of intergranular fracture (IGF) in these specimens, accompanied by grain boundary segregation of phosphorus. Theoretical models were developed to predict the parametric dependence of irradiation-enhanced phosphorus segregation on experimental variables. Using these parametric forms, along with the concept of a critical level of segregation for the onset of IGF instead of cleavage, a three mechanism trend curve has been developed. The form of this trend curve, taking into account IGF as well as matrix and copper embrittlement, is thus mechanistically based. The constants in the equation, however, are obtained by a statistical fit to the actual Charpy shift database.

  5. Stainless steel submerged arc weld fusion line toughness

    SciTech Connect (OSTI)

    Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

    1995-04-01T23:59:59.000Z

    This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.

  6. GALAXY HALO TRUNCATION AND GIANT ARC SURFACE BRIGHTNESS RECONSTRUCTION IN THE CLUSTER MACSJ1206.2-0847

    SciTech Connect (OSTI)

    Eichner, Thomas; Seitz, Stella; Monna, Anna [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Suyu, Sherry H. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Halkola, Aleksi [Institute of Medical Engineering, University of Luebeck, Ratzeburger Allee 160 23562 Luebeck (Germany); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, Adi [Institut fuer Theoretische Astrophysik, ZAH, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Coe, Dan; Postman, Marc; Koekemoer, Anton; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Rosati, Piero [ESO-European Southern Observatory, D-85748 Garching bei Muenchen (Germany); Grillo, Claudio; Host, Ole [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Balestra, Italo [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Zheng, Wei; Lemze, Doron [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Broadhurst, Tom [Department of Theoretical Physics, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); Moustakas, Leonidas [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, Pasadena, CA 91109 (United States); Molino, Alberto [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada E-18008 (Spain); and others

    2013-09-10T23:59:59.000Z

    In this work, we analyze the mass distribution of MACSJ1206.2-0847, particularly focusing on the halo properties of its cluster members. The cluster appears relaxed in its X-ray emission, but has a significant amount of intracluster light that is not centrally concentrated, suggesting that galaxy-scale interactions are still ongoing despite the overall relaxed state. The cluster lenses 12 background galaxies into multiple images and one galaxy at z = 1.033 into a giant arc and its counterimage. The multiple image positions and the surface brightness (SFB) distribution of the arc, which is bent around several cluster members, are sensitive to the cluster galaxy halo properties. We model the cluster mass distribution with a Navarro-Frenk-White profile and the galaxy halos with two parameters for the mass normalization and the extent of a reference halo assuming scalings with their observed near-infrared light. We match the multiple image positions at an rms level of 0.''85 and can reconstruct the SFB distribution of the arc in several filters to a remarkable accuracy based on this cluster model. The length scale where the enclosed galaxy halo mass is best constrained is about 5 effective radii-a scale in between those accessible to dynamical and field strong-lensing mass estimates on the one hand and galaxy-galaxy weak-lensing results on the other hand. The velocity dispersion and halo size of a galaxy with m{sub 160W,AB} = 19.2 and M{sub B,Vega} = -20.7 are {sigma} = 150 km s{sup -1} and r Almost-Equal-To 26 {+-} 6 kpc, respectively, indicating that the halos of the cluster galaxies are tidally stripped. We also reconstruct the unlensed source, which is smaller by a factor of {approx}5.8 in area, demonstrating the increase in morphological information due to lensing. We conclude that this galaxy likely has star-forming spiral arms with a red (older) central component.

  7. arc spray process: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Page Last Page Topic Index 1 Flow analysis and nozzle-shape optimization for the cold-gas dynamic-spray process Energy Storage, Conversion and Utilization Websites Summary:...

  8. Dynamics of osmosis in a porous medium

    E-Print Network [OSTI]

    Cardoso, Silvana S. S.; Cartwright, Julyan H. E.

    2014-11-12T23:59:59.000Z

    of the molecular behaviour to a mesoscale involving many pore lengths, connecting the atomic scale and the macroscopic scale, that is of utmost importance for the understanding of the role of osmosis in all its manifold applications in physics, chemistry...

  9. Gaseous and particulate emissions from a DC arc melter

    SciTech Connect (OSTI)

    Overcamp, T.J.; Speer, M.P.; Griner, S.J.; Cash, D.M. [Clemson Univ., Anderson, SC (United States)

    1997-12-31T23:59:59.000Z

    This paper presents the results of the gaseous and particulate emissions from eight experimental tests of a DC arc melter to treat simulated Savannah River soils contaminated with metals, surrogates for radionuclides, and organic debris. The gaseous analyses reported on the concentrations of oxygen, hydrogen, carbon monoxide, carbon dioxide, hydrogen, methane, nitric oxide, and nitrogen dioxide. The carbon dioxide concentration was high for all runs. For the runs with an air purge, the carbon monoxide concentration ranged up to 10% in the runs with the debris and 2% in the runs without debris. Hydrogen ranged up to 5% by with debris and up to 1% without debris. The methane concentration ranged up to 7,000 ppm{sub v} for the runs with debris and 2,000 ppm for the runs without debris. With a nitrogen purge, oxygen concentrations were less than 1%. The carbon dioxide concentrations ranged from 3 to 15%. Much of this carbon dioxide was probably due the carbonates added to the feed material. The carbon monoxide concentration ranged up to 20% with the debris and 7% without debris. Hydrogen was above 6% in with debris and up to 6% without debris. The methane concentration ranged up to 10,000 ppm{sub v} with debris and 4,000 ppm{sub v} without debris. The particulate concentrations exiting ranged from 32 to 145 g/m{sup 3}. From the chemical analyses, the primary elements were silicon and calcium. The CHN analyses indicated that carbon, probably as carbonates, are an additional component in the particulate matter. The estimated emissions were at a level of 3% or less for cerium, up to 7% for nickel, and 11 to 30% for cesium.

  10. High-power laser and arc welding of thorium-doped iridium alloys

    SciTech Connect (OSTI)

    David, S.A.; Liu, C.T.

    1980-05-01T23:59:59.000Z

    The arc and laser weldabilities of two Ir-0.3% W alloys containing 60 and 200 wt ppM Th have been investigated. The Ir-.03% W alloy containing 200 wt ppM Th is severely prone to hot cracking during gas tungsten-arc welding. Weld metal cracking results from the combined effects of heat-affected zone liquation cracking and solidification cracking. Scanning electron microscopic analysis of the fractured surface revealed patches of low-melting eutectic. The cracking is influenced to a great extent by the fusion zone microstructure and thorium content. The alloy has been welded with a continuous-wave high-power CO/sub 2/ laser system with beam power ranging from 5 to 10 kW and welding speeds of 8 to 25 mm/s. Successful laser welds without hot cracking have been obtained in this particular alloy. This is attributable to the highly concentrated heat source available in the laser beam and the refinement in fusion zone microstructure obtained during laser welding. Efforts to refine the fusion zone structure during gas tungsten-arc welding of Ir-0.3 % W alloy containing 60 wt ppM Th were partially successful. Here transverse arc oscillation during gas tungsten-arc welding refines the fusion zone structure to a certain extent. However, microstructural analysis of this alloy's laser welds indicates further refinement in the fusion zone microstructure than in that from the gas tungsten-arc process using arc oscillations. The fusion zone structure of the laser weld is a strong function of welding speed.

  11. Geochemistry of back arc basin volcanism in Bransfield Strait, Antarctica: Subducted contributions and along-axis variations

    E-Print Network [OSTI]

    Kurapov, Alexander

    /chemistry; 3640 Mineralogy and Petrology: Igneous petrology; 3655 Mineralogy and Petrology: Major element composition; 3670 Mineralogy and Petrology: Minor and trace element composition; KEYWORDS: back arc basin

  12. A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap

    E-Print Network [OSTI]

    Rathbun, Julie A.

    A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap v. 1 ............................................................................................................................5 2. Processing the images with ISIS

  13. Cosmology through arc statistics I: sensitivity to $\\Omega_m$ and $\\sigma_8$

    E-Print Network [OSTI]

    Boldrin, Michele; Meneghetti, Massimo; Moscardini, Lauro; Tormen, Giuseppe; Biviano, Andrea

    2015-01-01T23:59:59.000Z

    The next generation of large sky photometric surveys will finally be able to use arc statistics as a cosmological probe. Here we present the first of a series of papers on this topic. In particular, we study how arc counts are sensitive to the variation of two cosmological parameters: the (total) matter density parameter, $\\Omega_m$, and the normalisation of the primordial power spectrum, expressed in terms of $\\sigma_8$. Both these parameters influence the abundances of collapsed structures and their internal structure. We compute the expected number of gravitational arcs with various length-to-width ratios in mock light cones, by varying these cosmological parameters in the ranges $0.1\\leq\\Omega_m\\leq0.5$ and $0.6\\leq\\sigma_8\\leq 1$. We find that the arc counts dependence on $\\Omega_m$ and $\\sigma_8$ is similar, but not identical, to that of the halo counts. We investigate how the precision of the constraints on the cosmological parameters based on arc counts depends on the survey area. We find that the con...

  14. ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

    SciTech Connect (OSTI)

    Purandare, Yashodhan, E-mail: Y.Purandare@shu.ac.uk; Ehiasarian, Arutiun; Hovsepian, Papken [Nanotechnology Centre for PVD Research, Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Santana, Antonio [Ionbond AG Olten, Industriestrasse 211, CH-4600 Olten (Switzerland)

    2014-05-15T23:59:59.000Z

    Zirconium nitride (ZrN) coatings were deposited on 1??m finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5??m with hardness in the range of 30–40?GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

  15. Heat and mass transfer in the gas tungsten and gas metal arc welding processes

    SciTech Connect (OSTI)

    Watkins, A.D; Smartt, H.B.; Einerson, C.J.; Watkins, J.A.

    1990-01-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode was measured for a wide range of conditions suitable for mechanized welding. The results are given as (1) the arc efficiency and (2) the anode heat and current input distributions for various anode materials over a range of current and voltage. The nominal arc is Gaussian, {approximately}4 mm in diameter, with {approximately}75{percent}heat transfer efficiency. Variations from these values are discussed in terms of the electrical and thermal energy transport mechanisms. Heat transferred to the workpiece (cathode) during direct current, electrode positive gas metal arc welding (GMAW) was measured for various parameters applicable to machine welding. The results are presented as a function of electrode speed for changing voltages and contact tip to workpiece distances. The total heat transfer efficiency was nominally 85{percent} for a 0.89 mm diameter steel electrode using an argon-2{percent} oxygen shielding gas; the nominal heat transfer efficiency of the droplet component was 40{percent}. The average droplet temperatures ranged from 2400 to 3100 K, depending on the process parameters. A new method of measuring the heat transferred from the arc to the workpiece, using a boiling liquid nitrogen calorimeter, has been developed that gives rapid, accurate values. 20 refs., 8 figs., 2 tabs.

  16. Spectroscopic characterization and imaging of laser- and unipolar arc-induced plasmas

    SciTech Connect (OSTI)

    Aussems, Damien U. B., E-mail: d.aussems@differ.nl [FOM Institute DIFFER—Dutch Institute for Fundamental Energy Research, Nieuwegein, NL-3430 BE (Netherlands); Nishijima, Daisuke; Brandt, Christian; Doerner, Russell P. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093-0417 (United States); Cardozo, Niek J. Lopes [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, Eindhoven 5612 AZ (Netherlands)

    2014-08-14T23:59:59.000Z

    Tungsten plasmas induced by unipolar arcs were investigated using optical emission spectroscopy and imaging, and compared with laser-induced tungsten plasmas. The unipolar arcs were initiated in the linear-plasma simulator PISCES-A at UCSD under fusion relevant conditions. The electron temperature and density of the unipolar arc plasmas were in the range 0.5–0.7?eV and 0.7–2.0?×?10{sup 20?}m{sup ?3}, respectively, and increased with increasing negative bias voltage, but did not correlate with the surface temperature. In comparison, the electron temperature and density of the laser-induced plasmas were in the range 0.6–1.4?eV and 7?×?10{sup 19}–1?×?10{sup 22?}m{sup ?3}, respectively.

  17. Study on a negative hydrogen ion source with hot cathode arc discharge

    SciTech Connect (OSTI)

    Lin, S. H., E-mail: linshh@impcas.ac.cn; Fang, X. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China) [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Zhang, H. J.; Qian, C.; Ma, B. H.; Wang, H.; Li, X. X.; Zhang, X. Z.; Sun, L. T.; Zhang, Z. M.; Yuan, P.; Zhao, H. W. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)] [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-02-15T23:59:59.000Z

    A negative hydrogen (H{sup ?}) ion source with hot cathode arc discharge was designed and fabricated as a primary injector for a 10 MeV PET cyclotron at IMP. 1 mA dc H{sup ?} beam with ? {sub N,} {sub RMS} = 0.08 ??mm?mrad was extracted at 25 kV. Halbach hexapole was adopted to confine the plasma. The state of arc discharge, the parameters including filament current, arc current, gas pressure, plasma electrode bias, and the ratio of I{sub e{sup ?}}/I{sub H{sup ?}} were experimentally studied. The discussion on the result, and opinions to improve the source were given.

  18. Test plan for BWID Phase 2 electric arc melter vitrification tests

    SciTech Connect (OSTI)

    Soelberg, N.R.; Turner, P.C.; Oden, L.L.; Anderson, G.L.

    1994-10-01T23:59:59.000Z

    This test plan describes the Buried Waste Integrated Demonstration (BWID), Phase 2, electric arc melter, waste treatment evaluation tests to be performed at the US Bureau of Mines (USBM) Albany Research Center. The BWID Arc Melter Vitrification Project is being conducted to evaluate and demonstrate existing industrial arc melter technology for thermally treating mixed transuranic-contaminated wastes and soils. Phase 1 baseline tests, performed during fiscal year 1993 at the USBM, were conducted on waste feeds representing incinerated buried mixed wastes and soils. In Phase 2, surrogate feeds will be processed that represent actual as-retrieved buried wastes from the Idaho National Engineering Laboratory`s Subsurface Disposal Area at the Radioactive Waste Management Complex.

  19. Use of ArcGIS in Environmental Monitoring at Idaho National Laboratory

    SciTech Connect (OSTI)

    oertel; giles

    2007-06-01T23:59:59.000Z

    The Idaho National Laboratory is a U.S. Department of Energy site located in southeastern Idaho. The INL is required to perform environmental monitoring of anthropogenically introduced contaminants. One primary contaminant of interest is radioactive Cs-137 which is resident in INL soils due to past operational activities and atmospheric weapons testing. Collection of field data is performed using vehicle mounted and portable radiation detector units. All data is combined in ArcGIS and displayed over georeferenced satellite images and digital elevation models. The use of the ArcGIS geostatistical analysis package enhances the ability to look for areas of higher Cs-137 concentration. Combining current monitoring results with meteorological wind pattern maps allows for siting of new and improved monitoring locations. Use of the ArcGIS package provides an integrated analysis and mapping protocol for use in radioactive contaminant monitoring.

  20. Volumetric-modulated arc therapy (RapidArc) vs. conventional fixed-field intensity-modulated radiotherapy for {sup 18}F-FDG-PET-guided dose escalation in oropharyngeal cancer: A planning study

    SciTech Connect (OSTI)

    Teoh, May, E-mail: m.teoh@nhs.net [Department of Oncology, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Beveridge, Sabeena [Department of Medical Physics, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Wood, Katie; Whitaker, Stephen [Department of Oncology, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Adams, Elizabeth; Rickard, Donna; Jordan, Tom; Nisbet, Andrew [Department of Medical Physics, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Clark, Catharine H. [Department of Medical Physics, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex (United Kingdom)

    2013-04-01T23:59:59.000Z

    Fluorine-18-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG-PET)–guided focal dose escalation in oropharyngeal cancer may potentially improve local control. We evaluated the feasibility of this approach using volumetric-modulated arc therapy (RapidArc) and compared these plans with fixed-field intensity-modulated radiotherapy (IMRT) focal dose escalation plans. Materials and methods: An initial study of 20 patients compared RapidArc with fixed-field IMRT using standard dose prescriptions. From this cohort, 10 were included in a dose escalation planning study. Dose escalation was applied to {sup 18}F-FDG-PET–positive regions in the primary tumor at dose levels of 5% (DL1), 10% (DL2), and 15% (DL3) above standard radical dose (65 Gy in 30 fractions). Fixed-field IMRT and double-arc RapidArc plans were generated for each dataset. Dose-volume histograms were used for plan evaluation and comparison. The Paddick conformity index (CI{sub Paddick}) and monitor units (MU) for each plan were recorded and compared. Both IMRT and RapidArc produced clinically acceptable plans and achieved planning objectives for target volumes. Dose conformity was significantly better in the RapidArc plans, with lower CI{sub Paddick} scores in both primary (PTV1) and elective (PTV2) planning target volumes (largest difference in PTV1 at DL3; 0.81 ± 0.03 [RapidArc] vs. 0.77 ± 0.07 [IMRT], p = 0.04). Maximum dose constraints for spinal cord and brainstem were not exceeded in both RapidArc and IMRT plans, but mean doses were higher with RapidArc (by 2.7 ± 1 Gy for spinal cord and 1.9 ± 1 Gy for brainstem). Contralateral parotid mean dose was lower with RapidArc, which was statistically significant at DL1 (29.0 vs. 29.9 Gy, p = 0.01) and DL2 (29.3 vs. 30.3 Gy, p = 0.03). MU were reduced by 39.8–49.2% with RapidArc (largest difference at DL3, 641 ± 94 vs. 1261 ± 118, p < 0.01). {sup 18}F-FDG-PET–guided focal dose escalation in oropharyngeal cancer is feasible with RapidArc. Compared with conventional fixed-field IMRT, RapidArc can achieve better dose conformity, improve contralateral parotid sparing, and uses fewer MU.

  1. A study of the precursor effect in an arc-driven shock tube

    E-Print Network [OSTI]

    Reed, James Alan

    1969-01-01T23:59:59.000Z

    A STUDY OF THE PRECURSOR EFFECT IN AN ARC-DRIVEN SHOCK TISE A Thesis by JAMES ALAN REED Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1969 Major... Subject: Aerospace Engineering A STUDY OF THE PRECURSOR EFFECT IN AN ARC-DRIVEN SHOCK TUBE A Thesis by JAMES ALAN REED Approved as to style and content by: (Chairman of Committee) (He p ) (Member) (Memb er) (Member) (Member) (Member) 11ay 1969...

  2. Subduction Controls of Hf and Nd Isotopes in Lavas of the Aleutian Island Arc

    SciTech Connect (OSTI)

    Yogodzinski, Gene; Vervoort, Jeffery; Brown, Shaun Tyler; Gerseny, Megan

    2010-08-29T23:59:59.000Z

    The Hf and Nd isotopic compositions of 71 Quaternary lavas collected from locations along the full length of the Aleutian island arc are used to constrain the sources of Aleutian magmas and to provide insight into the geochemical behavior of Nd and Hf and related elements in the Aleutian subduction-magmatic system. Isotopic compositions of Aleutian lavas fall approximately at the center of, and form a trend parallel to, the terrestrial Hf-Nd isotopic array with {var_epsilon}{sub Hf} of +12.0 to +15.5 and {var_epsilon}{sub Nd} of +6.5 to +10.5. Basalts, andesites, and dacites within volcanic centers or in nearby volcanoes generally all have similar isotopic compositions, indicating that there is little measurable effect of crustal or other lithospheric assimilation within the volcanic plumbing systems of Aleutian volcanoes. Hafnium isotopic compositions have a clear pattern of along-arc increase that is continuous from the eastern-most locations near Cold Bay to Piip Seamount in the western-most part of the arc. This pattern is interpreted to reflect a westward decrease in the subducted sediment component present in Aleutian lavas, reflecting progressively lower rates of subduction westward as well as decreasing availability of trench sediment. Binary bulk mixing models (sediment + peridotite) demonstrate that 1-2% of the Hf in Aleutian lavas is derived from subducted sediment, indicating that Hf is mobilized out of the subducted sediment with an efficiency that is similar to that of Sr, Pb and Nd. Low published solubility for Hf and Nd in aqueous subduction fluids lead us to conclude that these elements are mobilized out of the subducted component and transferred to the mantle wedge as bulk sediment or as a silicate melt. Neodymium isotopes also generally increase from east to west, but the pattern is absent in the eastern third of the arc, where the sediment flux is high and increases from east to west, due to the presence of abundant terrigenous sediment in the trench east of the Amlia Fracture Zone, which is being subducting beneath the arc at Seguam Island. Mixing trends between mantle wedge and sediment end members become flatter in Hf-Nd isotope space at locations further west along the arc, indicating that the sediment end member in the west has either higher Nd/Hf or is more radiogenic in Hf compared to Nd. This pattern is interpreted to reflect an increase in pelagic clay relative to the terrigenous subducted sedimentary component westward along the arc. Results of this study imply that Hf does not behave as a conservative element in the Aleutian subduction system, as has been proposed for some other arcs.

  3. Datamart use for complex data retrieval in an ArcIMS application

    SciTech Connect (OSTI)

    Scherma, S. (Steven); Bolivar, Stephen L.

    2004-01-01T23:59:59.000Z

    This paper describes the use of datamarts and data warehousing concepts to expedite retrieval and display of complex attribute data from multi-million record databases. Los Alamos National Laboratory has developed an Internet application (SMART) using ArcIMS that relies on datamarts to quickly retrieve attribute data, associated with, but not contained within GIS layers. The volume of data and the complex relationships within the transactional database made data display within ArcIMS impractical without the use of datamarts. The technical issues and solutions involved in the development are discussed.

  4. Mesure de la densit lectronique et carts l'quilibre de composition dans les arcs de SF6-N2

    E-Print Network [OSTI]

    Boyer, Edmond

    1325 Mesure de la densité électronique et écarts à l'équilibre de composition dans les arcs de SF6 mesurée dans des arcs stabilisés brûlant dans des mélanges SF6-N2, par des techniques de spectroscopie d électronique en fonction du pourcentage de SF6 dans le mélange et en fonction de l'intensité du courant sont en

  5. Pleistocene hinterland evolution of the active Banda Arc: Surface uplift and neotectonic deformation recorded by coral terraces at Kisar, Indonesia

    E-Print Network [OSTI]

    Seamons, Kent E.

    deformation recorded by coral terraces at Kisar, Indonesia AND Hinterland emergence of the active Banda arc-continent collision: Metamorphism, geochronology, and structure of the uplifted Kisar Atoll, Indonesia and related Banda Arc: surface uplift and neotectonic deformation recorded by coral terraces at Kisar, Indonesia

  6. Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade

    E-Print Network [OSTI]

    Grujicic, Mica

    Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor metal arc welding (GMAW) butt-joining process has been modeled using a two-way fully coupled, transient in the form of heat, and the mechanical material model of the workpiece and the weld is made temperature

  7. Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation and residual stresses

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation.Bellet@mines-paristech.fr ABSTRACT The joining of high thickness steel sheets by means of hybrid Laser/GMAW welding processes of the workpiece borders. Two finite elements models are presented to illustrate: (i) A hybrid arc/laser welding

  8. Characterization of Gas Metal Arc Welding welds obtained with new high Cr-Mo ferritic stainless steel filler wires

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Characterization of Gas Metal Arc Welding welds obtained with new high Cr-Mo ferritic stainless Several compositions of metal cored filler wire were manufactured to define the best welding conditions for homogeneous welding, by Gas Metal Arc Welding (GMAW) process, of a modified AISI 444 ferritic stainless steel

  9. Plasma Chemistry and Plasma Processing, Vol. 12, No.4, 1992 Infrared Radiation from an Arc Plasma and Its

    E-Print Network [OSTI]

    Eagar, Thomas W.

    in the electric field of a charged particle, radiation is emitted. In terms of radiation intensity, electronB ) Plasma Chemistry and Plasma Processing, Vol. 12, No.4, 1992 Infrared Radiation from an Arc ifinfraredradiation from an arc plasma can fie used for diagnostic purposes. Tire properties of IR radiation

  10. EMAG2: A 2arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic

    E-Print Network [OSTI]

    Müller, Dietmar

    grid for the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc min to 2EMAG2: A 2­arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, I-19020 Fezzano, Italy [1] A global Earth Magnetic Anomaly Grid (EMAG2) has been compiled from

  11. Visible Light Emissions during Gas Tungsten Arc Welding and Its Application to Weld

    E-Print Network [OSTI]

    Eagar, Thomas W.

    emission, were also determined. An improved image of the weld pool can be obtained by operating within will require development of new sensor systems. As the "Yelding arc is a harsh environment, noncontacting to control joint tracking and weld E. W. KIM, C. ALLEMAND and T. W. EAGAR are with the Massachusetts

  12. Bifurcation of Singular Arcs in an Optimal Control Problem for Cancer Immune System Interactions under Treatment

    E-Print Network [OSTI]

    Ledzewicz, Urszula

    , 63130-4899, hms@wustl.edu Abstract-- A mathematical model for cancer treatment that includesBifurcation of Singular Arcs in an Optimal Control Problem for Cancer Immune System Interactions under Treatment Urszula Ledzewicz Dept. of Mathematics and Statistics, Southern Illinois University

  13. Magnetic properties of carbon-coated, ferromagnetic nanoparticles produced by a carbon-arc method

    E-Print Network [OSTI]

    McHenry, Michael E.

    Magnetic properties of carbon-coated, ferromagnetic nanoparticles produced by a carbon-arc method E to generate carbon-coated transition metal (TM) and TM-carbide nanocrystallites. The magnetic nanocrystallites report here on the synthesis and separation of carbon-coated ferromagnetic transition metal (TM) and TM

  14. Method for removal of phosgene from boron trichloride. [DOE patent application; mercury arc lamp

    DOE Patents [OSTI]

    Freund, S.M.

    1981-09-03T23:59:59.000Z

    Selective ultraviolet photolysis using an unfiltered mercury arc lamp has been used to substantially reduce the phosgene impurity in a mixture of boron trichloride and phosgene. Infrared spectrophotometric analysis of the sample before and after irradiation shows that it is possible to highly purify commercially available boron trichloride with this method.

  15. ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education

    E-Print Network [OSTI]

    Arnold, Jonathan

    ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education Case, exhilarating and vital to the issues of the day. This lens on graduate education is traditional, time in the academy. In addition to creating new knowledge, graduate education also contributes to the public good

  16. ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education

    E-Print Network [OSTI]

    Arnold, Jonathan

    1 ARCS FOUNDATION GLOBAL IMPACT AWARD Global Health, Public Good and Graduate Education Case, exhilarating and vital to the issues of the day. This lens on graduate education is traditional, time in the academy. In addition to creating new knowledge, graduate education also contributes to the public good

  17. CHANGES IN SOLIDIFICATION MODE, AND THE MEASUREMENT OF COOLING RATES FOLLOWING SOLIDIFICATION DURING ARC WELDING

    E-Print Network [OSTI]

    Cambridge, University of

    SOLIDIFICATION DURING ARC WELDING 2.1 INTRODUCTION The solidification process in a weld pool has been shown to have a considerable in- fluence upon the properties of the resultant weld. It influences elements, and hence the homogeneity of the weld. Previous work on the cooling behaviour of welds (Garland

  18. Improved Microstructure and Properties of 6061 Aluminum Alloy Weldments Using a Double-Sided Arc Welding

    E-Print Network [OSTI]

    Zhang, YuMing

    Welding Process Y.M. ZHANG, C. PAN, and A.T. MALE Due to its popularity and high crack sensitivity, 6061 aluminum alloy was selected as a test material for the newly developed double-sided arc welding (DSAW systematically. The percentage of fine equiaxed grains in the fully penetrated welds is greatly increased

  19. Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding M. Grujicic, S. Ramaswami, J.S. Snipes, R. Yavari, A. Arakere, C.-F. Yen, and B.A. Cheeseman-mechanical finite-element procedure is developed to model conventional gas metal arc welding (GMAW) butt of the workpiece and the weld temperature- dependent and by allowing the potential work of plastic deformation

  20. FY10 Transition Plan For CCDD Applied Research Center (ARC) on Precipitation

    E-Print Network [OSTI]

    FY10 Transition Plan For CCDD Applied Research Center (ARC) on Precipitation Pingping Xie Climate- Statement of transition goal Due to the manual operation nature, this processing cannot be converted transition to date N/A C- Location of data set production, identification of production team (including

  1. A new family of locally 5arc transitive Michael Giudici a, Cai Heng Li a

    E-Print Network [OSTI]

    Giudici, Michael

    A new family of locally 5­arc transitive graphs Michael Giudici a, Cai Heng Li a Cheryl E. Praeger@maths.uwa.edu.au (Cai Heng Li), praeger@maths.uwa.edu.au (Cheryl E. Praeger). Preprint submitted to Elsevier Science 17

  2. Lithium isotopes in island arc geothermal systems: Guadeloupe, Martinique (French West Indies) and experimental approach

    E-Print Network [OSTI]

    Boyer, Edmond

    Lithium isotopes in island arc geothermal systems: Guadeloupe, Martinique (French West Indies and the Diamant areas). The lithium isotopic signatures of the geothermal fluids collected from deep reservoirs during formation of Li- bearing secondary minerals by the uptake of lithium into the alteration minerals

  3. Discovery of Red Selected Arcs at z=4.04 behind Abell 2390

    E-Print Network [OSTI]

    Brenda Frye; Tom Broadhurst

    1997-12-08T23:59:59.000Z

    We describe the properties of a system of red arcs discovered at z=4.04 around the cluster A2390 ($z=0.23$). These arcs are images of a single galaxy, where the lensing is compounded by an elliptical cluster member lying close to the critical curve of the cluster. The combined magnification is estimated to be $\\sim 20$, using HST images, depending the gradient of the model potentials, implying an unlensed magnitude for the source of $I_{AB}=25.5$. Keck spectroscopy reveals a continuum well fitted by B-stars and attenuated by the Lyman-series forest with an opacity consistent with z$\\sim$4 QSO spectra, making the arcs relatively red. Damped Ly$\\alpha$ absorption is observed at the source redshift with a relatively high column, n$_{HI}=3\\times 10^{21}$. Curiously, Ly$\\alpha$ emission is spatially separated ($\\sim 0.5$kpc) from the bright stellar continuum and lies $\\sim$ 300Km/s redward of interstellar absorption lines at z=4.04. Similar redwardl of young galaxies. Finally, we briefly comment on the notorious ``straight arc'' in A2390, which is resolved into two unrelated galaxies at z=0.913 and z=1.033.

  4. The Magnetite Crisis in the Evolution of Arc-related Magmas and the Initial

    E-Print Network [OSTI]

    Lee, Cin-Ty Aeolus

    and back-arc magma series is their association with ores of the rare, but economically important metals Au of these metals is not straightforward. For Au, one of the rarest metals on Earth, with a primitive mantle RESEARCH SCHOOL OF EARTH SCIENCES, AUSTRALIAN NATIONAL UNIVERSITY, CANBERRA, ACT 0200, AUSTRALIA RECEIVED

  5. (Smart) Look-Ahead Arc Consistency and the Pursuit of CSP Tractability

    E-Print Network [OSTI]

    Dalmau, Victor

    (Smart) Look-Ahead Arc Consistency and the Pursuit of CSP Tractability Hubie Chen 1 and V#19. The constraint satisfaction problem (CSP) can be formu- lated as the problem of deciding, given a pair (A; B) of relational struc- tures, whether or not there is a homomorphism from A to B. Although the CSP is in general

  6. Numerical Analysis of Metal Transfer in Gas Metal Arc Welding under Modified Pulsed Current Conditions

    E-Print Network [OSTI]

    Zhang, YuMing

    causes a thermal load too high to apply to thin sectioned or heat-sensitive materials. In an effort was assumed as the boundary condition for the calculation of the electromagnetic force. The calculations were agreement between calculation and experimental results. I. INTRODUCTION IN gas metal arc welding (GMAW

  7. Effect of Electric Arc Furnace Bag House Dust on Concrete Durability Researcher: Fahad Al-Mutlaq

    E-Print Network [OSTI]

    Birmingham, University of

    Effect of Electric Arc Furnace Bag House Dust on Concrete Durability Researcher: Fahad Al billions of dollars annually. While steel is normally protected from corrosion in concrete by a passive of the effects of addition of Bag House Dust (BHD) on aspects of concrete durability. BHD is a fine powder

  8. Convection in Arc Weld Pools Electromagnetic and surface tension forces are shown to

    E-Print Network [OSTI]

    Eagar, Thomas W.

    Convection in Arc Weld Pools Electromagnetic and surface tension forces are shown to dominate flow tension forces. It is shown that the electromag- netic and surface tension forces domi- nate the flow by experimental measurements of segrega- tion in the weld pool. It is also shown that the surface tension driven

  9. Anode-cathode voltage drop of a rotating arc in an auto-expansion circuit-breaker filled with SF6-N2 mixtures

    SciTech Connect (OSTI)

    Beauvois, V.; Legros, W.; Scarpa, P. [Inst. Montefiore, Liege (Belgium)] [and others

    1995-12-31T23:59:59.000Z

    In auto-expansion circuit-breakers, the power dissipated by the arc itself heats the surrounding gas, inducing a pressure build up in the {open_quotes}upstream volume{close_quotes} and giving rise to a gas flow which blows the extinguishing arc. Moreover, in the studied apparatus, a magnetic field, due to the current flowing in a coil, provides arc radial stability and leads to arc rotation which efficiently reduces electrode erosion. In such a circuit-breaker, it is obvious that arc-gas and arc-electrode interactions are essential and govern. the energy balance in the plasma region. This paper deals more specifically with the phenomena occurring at the arc-electrode interfaces. It relates results of experiments carried out to determine the anode-cathode voltage drop when the apparatus is filled with different SF6-N2 mixtures.

  10. Geochemical tracers of processes affecting the formation of seafloor hydrothermal fluids and deposits in the Manus back-arc basin

    E-Print Network [OSTI]

    Craddock, Paul R

    2009-01-01T23:59:59.000Z

    Systematic differences in trace element compositions (rare earth element (REE), heavy metal, metalloid concentrations) of seafloor vent fluids and related deposits from hydrothermal systems in the Manus back-arc basin ...

  11. Development of an ArcGIS interface and design of a geodatabase for the soil and water assessment tool 

    E-Print Network [OSTI]

    Valenzuela Zapata, Milver Alfredo

    2004-09-30T23:59:59.000Z

    This project presents the development and design of a comprehensive interface coupled with a geodatabase (ArcGISwat 2003), for the Soil and Water Assessment Tool (SWAT). SWAT is a hydrologically distributed, lumped parameter ...

  12. Measurement and modeling of Ar/H2/CH4 arc jet discharge chemical vapor deposition reactors. I. Intercomparison

    E-Print Network [OSTI]

    Bristol, University of

    of thin, polycrystalline diamond films, and the results of a two-dimensional r,z computer model domains. dc arc jets offer considerable advantages as a route to deposition of polycrystalline diamond

  13. Presented in Conway, Lee, Merrimack and Plymouth, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Spring 2013

    E-Print Network [OSTI]

    New Hampshire, University of

    , as well as, conduct geospatial analysis. Participants will learn to: symbolize GIS data; add labelsPresented in Conway, Lee, Merrimack and Plymouth, NH by the UNHCE Geospatial Outreach Program Arc

  14. Presented in Concord, Merrimack and West Lebanon, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Fall 2012

    E-Print Network [OSTI]

    New Hampshire, University of

    , as well as, conduct geospatial analysis. Participants will learn to: symbolize GIS data; add labelsPresented in Concord, Merrimack and West Lebanon, NH by the UNHCE Geospatial Outreach Program Arc

  15. Presented in Lee and Concord, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Winter 2013

    E-Print Network [OSTI]

    New Hampshire, University of

    .1 to produce effective maps, edit and create GIS data, as well as, conduct geospatial analysis. ParticipantsPresented in Lee and Concord, NH by the UNHCE Geospatial Outreach Program ArcGIS Workshops Winter

  16. Puzzling differences in bismuth and lead plasmas: evidence for the significant role of neutrals in cathodic vacuum arcs

    E-Print Network [OSTI]

    Anders, Andre; Yushkov, Georgy Yu.

    2007-01-01T23:59:59.000Z

    vacuum arcs for (a) lead plasma, (b) bismuth plasma. Arcproperties 16,17,22 of lead and bismuth. Pb Bi Atomic numberdifferences in bismuth and lead plasmas: evidence for the

  17. Development of an ArcGIS interface and design of a geodatabase for the soil and water assessment tool

    E-Print Network [OSTI]

    Valenzuela Zapata, Milver Alfredo

    2004-09-30T23:59:59.000Z

    the Geodatabase object model and concepts from hydrological data models such as ArcHydro. It also incorporates uncertainty analysis on the process of modeling. This interface aims to further direct communication and integration with other hydrologic models...

  18. A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anders, Andre

    2014-10-01T23:59:59.000Z

    High power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in this review, an overview is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.

  19. Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhu, Yuankun; Mendelsberg, Rueben J.; Zhu, Jiaqi; Han, Jiecai; Anders, Andre

    2013-01-01T23:59:59.000Z

    Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23 10-5 cm, high electron mobility of 142 cm2/Vs, and mean transmittance over 80percent from 500-1250 nm (including the glass substrate).more »These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.« less

  20. Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhu, Yuankun [Harbin Institute of Technology (China). Center for Composite Materials and Structures; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Plasma Applications Group; Mendelsberg, Rueben J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Plasma Applications Group and Molecular Foundry; Zhu, Jiaqi [Harbin Institute of Technology (China). Center for Composite Materials and Structures; Han, Jiecai [Harbin Institute of Technology (China). Center for Composite Materials and Structures; Anders, Andre [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Plasma Applications Group

    2013-01-01T23:59:59.000Z

    Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23 10-5 cm, high electron mobility of 142 cm2/Vs, and mean transmittance over 80percent from 500-1250 nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.

  1. Plasma arc melting of a 80 wt % tantalum-20 wt % titanium alloy

    SciTech Connect (OSTI)

    Dunn, P.S.; Patterson, R.A.

    1994-10-01T23:59:59.000Z

    An alloy of 80wt% tantalum-20wt% titanium is being considered for use in an oxidizing and highly corrosive liquid metal application. The high melting point of the alloy, 2400 C, and other physical properties narrowed the possible melting techniques. Previous melting experience with these materials by electron beam resulted in extensive vaporization of the titanium during the melt and poor chemical homogeneity. A technique has been developed using plasma arc melting to melt refractory alloys with very dissimilar densities and vapor pressures. The 80Ta--20Ti alloy falls into this category with the density of tantalum 16.5 g/cc and that of titanium 4.5 g/cc. The melting of these materials is further complicated by the high melting point of tantalum( 3020 C) and the relatively low boiling point of titanium( 3287 C). The plasma arc melting technique described results in good chemical homogeneity with ingot size quantities of material.

  2. A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)

    SciTech Connect (OSTI)

    Anders, Andre

    2014-08-17T23:59:59.000Z

    High power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in this review, an overview is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.

  3. Use of vacuum arc plasma guns for a metal puff Z-pinch system

    SciTech Connect (OSTI)

    Rousskikh, A. G.; Zhigalin, A. S.; Oreshkin, V. I.; Chaikovsky, S. A.; Labetskaya, N. A. [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Baksht, R. B. [Tel Aviv University, Electrical Discharge and Plasma Laboratory, Tel Aviv 69101 (Israel)

    2011-09-15T23:59:59.000Z

    The performance of a metal puff Z-pinch system has been studied experimentally. In this type of system, the initial cylindrical shell 4 cm in diameter was produced by ten plasma guns. Each gun initiates a vacuum arc operating between magnesium electrodes. The net current of the guns was 80 kA. The arc-produced plasma shell was compressed by using a 450-kA, 450-ns driver, and as a result, a plasma column 0.3 cm in diameter was formed. The electron temperature of the plasma reached 400 eV at an average ion concentration of 1.85 {center_dot} 10{sup 18} cm{sup -3}. The power of the Mg K-line radiation emitted by the plasma for 15-30 ns was 300 MW/cm.

  4. THE REMOVAL OF CARBON/BEUTERIUM FROM STAINLESS STEEL AND TUNGSTEN BY TRANSFERRED-ARC CLEANING

    SciTech Connect (OSTI)

    K. J. HOLLIS; R. G. CASTRO; ET AL

    2001-04-01T23:59:59.000Z

    Tungsten and stainless steel samples have been contaminated with deuterium and carbon to simulate deposited layers in magnetic-confinement fusion devices. Deuterium and carbon were co-deposited onto the sample surfaces using a deuterium plasma seeded with varying amounts of deuterated methane. Deuterium was also implanted into the samples in an accelerator to simulate hydrogen isotope ion implantation conditions in magnetic confinement fusion devices. Cathodic arc, or transferred-arc (TA) cleaning was employed to remove the deposits from the samples. The samples were characterized by ion beam analysis both before and after cleaning to determine deuterium and carbon concentrations present. The deuterium content was greatly reduced by the cleaning thus demonstrating the possibility of using the TA cleaning technique for removing deuterium and/or tritium from components exposed to D-T fuels. Removal of surface layers and significant reduction of subsurface carbon concentrations was also observed.

  5. Optoelectronic ally automated system for carbon nanotubes synthesis via arc-discharge in solution

    SciTech Connect (OSTI)

    Bera, Debasis; Brinley, Erik; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Kabes, Bradley [Surface Engineering and Nanotechnology Facility - SNF, Advanced Materials Processing and Analysis Center - AMPAC, and Mechanical, Materials and Aerospace Engineering - MMAE, University of Central Florida - UCF, 4000 Central Florida Blvd., Eng 1, no. 381, Orlando, Florida 32816 (United States); Advanced Materials Processing and Analysis Center - AMPAC and Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Eng 1, no. 381, Orlando, Florida 32816 (United States); NSF REU Site (UCF), Department of Chemical Engineering, University of Minnesota, Duluth, Minnesota 55803 (United States)

    2005-03-01T23:59:59.000Z

    The method of arc discharge in the solution is unique and inexpensive route for synthesis of the carbon nanotubes (CNTs), carbon onions, and other carbon nanostructures. Such a method can be used for in situ synthesis of CNTs decorated with nanoparticles. Herein, we report a simple and inexpensive optoelectronically automated system for arc discharge in solution synthesis of CNTs. The optoelectronic system maintains a constant gap between the two electrodes allowing a continuous synthesis of the carbon nanostructures. The system operates in a feedback loop consisting of an electrode-gap detector and an analog electronic unit, as controller. This computerized feeding system of the anode was used for in situ nanoparticles incorporated CNTs. For example, we have successfully decorated CNTs with ceria, silica, and palladium nanoparticles. Characterizations of nanostructures are performed using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive spectroscopy, and scanning electron microscopy.

  6. A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anders, Andre

    2014-10-01T23:59:59.000Z

    High power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in this review, an overviewmore »is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.« less

  7. Field-driven Polarization and Domain Dynamics of Ferroelectric...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    March 1, 2012 - 10:00am SSRL Conference Room 137-226 Paul G. Evans, Materials Science and Engineering, University of Wisconsin-Madison The atomic-scale periodicity of...

  8. An arc control and protection system for the JET lower hybrid antenna based on an imaging system

    SciTech Connect (OSTI)

    Figueiredo, J., E-mail: joao.figueiredo@jet.efda.org [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal and EFDA-CSU, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Mailloux, J.; Kirov, K.; Kinna, D.; Stamp, M.; Devaux, S.; Arnoux, G.; Edwards, J. S.; Stephen, A. V.; McCullen, P.; Hogben, C. [EURATOM/CCFE Fusion Association, Culham Science Center, Abingdon OX14 3DB (United Kingdom)

    2014-11-15T23:59:59.000Z

    Arcs are the potentially most dangerous events related to Lower Hybrid (LH) antenna operation. If left uncontrolled they can produce damage and cause plasma disruption by impurity influx. To address this issue an arc real time control and protection imaging system for the Joint European Torus (JET) LH antenna has been implemented. The LH system is one of the additional heating systems at JET. It comprises 24 microwave generators (klystrons, operating at 3.7 GHz) providing up to 5 MW of heating and current drive to the JET plasma. This is done through an antenna composed of an array of waveguides facing the plasma. The protection system presented here is based primarily on an imaging arc detection and real time control system. It has adapted the ITER like wall hotspot protection system using an identical CCD camera and real time image processing unit. A filter has been installed to avoid saturation and spurious system triggers caused by ionization light. The antenna is divided in 24 Regions Of Interest (ROIs) each one corresponding to one klystron. If an arc precursor is detected in a ROI, power is reduced locally with subsequent potential damage and plasma disruption avoided. The power is subsequently reinstated if, during a defined interval of time, arcing is confirmed not to be present by image analysis. This system was successfully commissioned during the restart phase and beginning of the 2013 scientific campaign. Since its installation and commissioning, arcs and related phenomena have been prevented. In this contribution we briefly describe the camera, image processing, and real time control systems. Most importantly, we demonstrate that an LH antenna arc protection system based on CCD camera imaging systems works. Examples of both controlled and uncontrolled LH arc events and their consequences are shown.

  9. Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

    DOE Patents [OSTI]

    Brown, I.G.; MacGill, R.A.; Galvin, J.E.; Ogletree, D.F.; Salmeron, M.

    1998-11-24T23:59:59.000Z

    A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing. 8 figs.

  10. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    DOE Patents [OSTI]

    Heiple, C.R.; Burgardt, P.

    1984-03-13T23:59:59.000Z

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  11. Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

    DOE Patents [OSTI]

    Brown, Ian G. (Berkeley, CA); MacGill, Robert A. (Richmond, CA); Galvin, James E. (Emmeryville, CA); Ogletree, David F. (El Cerrito, CA); Salmeron, Miquel (El Cerrito, CA)

    1998-01-01T23:59:59.000Z

    A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing.

  12. Method of detecting the direction of arcing faults on power distribution feeders

    E-Print Network [OSTI]

    Fernando, W. Anand Krisantha

    1992-01-01T23:59:59.000Z

    lines served by the same substation, resulting in false indications on the other feeders, in the case of an arcing fault. Two primary methods of detecting directionality of power system faults exist, impedance relaying and traveling wave relaying... is of significant magnitude to cause a current reversal in the case of a reverse fault [18]. 2. Traveling Wave Relaying The need for more accurate and fast detection of fault and direction of very high voltage transmission lines, was the base of invention...

  13. Exploring high temperature phenomena related to post-detonation using an electric arc

    SciTech Connect (OSTI)

    Dai, Z. R., E-mail: dai1@llnl.gov; Crowhurst, J. C.; Grant, C. D.; Knight, K. B.; Tang, V.; Chernov, A. A.; Cook, E. G.; Lotscher, J. P.; Hutcheon, I. D. [Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States)

    2013-11-28T23:59:59.000Z

    We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100??s. Samples took the form of a 4??m-thick film deposited onto 8 pairs of 17??m-thick Cu electrodes supported on a 25??m-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO{sub 2}, UC{sub 2}, UCu{sub 5},) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ?2300?K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.

  14. The characteristics of arcing faults in 480-volt power distribution systems

    E-Print Network [OSTI]

    Shih, Yu?

    1994-01-01T23:59:59.000Z

    December 1994 Major Subject: Electrical Engineering THE CHARACTERISTICS OF ARCING FAULTS IN 480-VOLT POWER DISTRIBUTION SYSTEMS A Thesis by YU SHI Submitted to Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE Approved as to style and content by: B. Don Russell (Chair of Committee) . M. Hua g (Member) , 24 . Yurt (Member) M. Kezunovic (Member) A. D. Patton (Head of Department) December 1994 Major Subject; Electrical Engineering...

  15. Optical tuning in the arcs and final focus sections of the Stanford Linear Collider

    SciTech Connect (OSTI)

    Bambade, P.S.

    1989-03-01T23:59:59.000Z

    In this thesis, we present the experimental tuning procedures developed for the Arcs and for the Final Focus Section of the Stanford Linear Collider (SLC). Such tuning is necessary to maximize the luminosity, by minimizing the beam size at the interaction point, and to reduce backgrounds in the experiment. In the final Focus Section, the correction strategy must result from the principles of the optical design, which is based on cancellations between second order aberrations, and on the ability to measure micron-size beams typical of the SLC. In the Arcs, the corrections were designed after the initial commissioning, to make the system more error-tolerant, through a modification in the optical design, and to enable adjustments of the beam phase-space a the injection to the Final Focus System, through a harmonic perturbation technique inspired from circular accelerators. Although the overall optimization of the SLC is not entirely finished, an almost optimal set-up has been achieved for the optics of the Arcs and of the Final Focus Section. Beams with transverse sizes close to the nominal ones, of a few microns, have been obtained at the interaction point. We present and discuss our results and the optical limits to the present performance. 24 refs., 25 figs., 2 tabs.

  16. Preliminary photovoltaic arc-fault prognostic tests using sacrificial fiber optic cabling.

    SciTech Connect (OSTI)

    Johnson, Jay; Blemel, Kenneth D. [Sentient Business Systems, Inc., Albuquerque, NM; Peter, Francis [Sentient Business Systems, Inc., Albuquerque, NM

    2013-02-01T23:59:59.000Z

    Through the New Mexico Small Business Assistance Program, Sandia National Laboratories worked with Sentient Business Systems, Inc. to develop and test a novel photovoltaic (PV) arc-fault detection system. The system operates by pairing translucent polymeric fiber optic sensors with electrical circuitry so that any external abrasion to the system or internal heating causes the fiber optic connection to fail or detectably degrade. A periodic pulse of light is sent through the optical path using a transmitter-receiver pair. If the receiver does not detect the pulse, an alarm is sounded and the PV system can be de-energized. This technology has the unique ability to prognostically determine impending failures to the electrical system in two ways: (a) the optical connection is severed prior to physical abrasion or cutting of PV DC electrical conductors, and (b) the polymeric fiber optic cable melts via Joule heating before an arc-fault is established through corrosion. Three arc-faults were created in different configurations found in PV systems with the integrated fiber optic system to determine the feasibility of the technology. In each case, the fiber optic cable was broken and the system annunciated the fault.

  17. Mechanism of Synthesis of Ultra-Long Single Wall Carbon Nanotubes in Arc Discharge Plasma

    SciTech Connect (OSTI)

    Keidar, Michael [George Washington University] [George Washington University

    2013-06-23T23:59:59.000Z

    In this project fundamental issues related to synthesis of single wall carbon nanotubes (SWNTs), which is relationship between plasma parameters and SWNT characteristics were investigated. Given that among plasma-based techniques arc discharge stands out as very advantageous in several ways (fewer defects, high flexibility, longer lifetime) this techniques warrants attention from the plasma physics and plasma technology standpoint. Both experimental and theoretical investigations of the plasma and SWNTs synthesis were conducted. Experimental efforts focused on plasma diagnostics, measurements of nanostructures parameters, and nanoparticle characterization. Theoretical efforts focused to focus on multi-dimensional modeling of the arc discharge and single wall nanotube synthesis in arc plasmas. It was demonstrated in experiment and theoretically that controlling plasma parameters can affect nanostucture synthesis altering SWNT properties (length and diameter) and leading to synthesis of new structures such as a few-layer graphene. Among clearly identified parameters affecting synthesis are magnetic and electric fields. Knowledge of the plasma parameters and discharge characteristics is crucial for ability to control synthesis process by virtue of both magnetic and electric fields. New graduate course on plasma engineering was introduced into curriculum. 3 undergraduate students were attracted to the project and 3 graduate students (two are female) were involved in the project. Undergraduate student from Historically Black University was attracted and participated in the project during Summer 2010.

  18. Bias and self-bias of magnetic macroparticle filters for cathodic arc plasmas

    SciTech Connect (OSTI)

    Byon, Eungsun; Anders, Andre

    2002-12-01T23:59:59.000Z

    Curved magnetic filters are often used for the removal of macroparticles from cathodic arc plasmas. This study addresses the need to further reduce losses and improving plasma throughput. The central figure of merit is the system coefficient Kappa defined as filtered ion current normalized by the plasma-producing arc current. The coefficient Kappa is investigated as a function of DC and pulsed magnetic field operation, magnetic field strength, external electric bias, and arc amplitude. It increases with positive filter bias but saturates at about 15 V for relatively low magnetic field ({approx}10 mT), whereas stronger magnetic fields lead to higher Kappa with saturation at about 25 V. Further increase of positive bias reduces Kappa. These findings are true for both pulsed and DC filters. Bias of pulsed filters has been realized using the voltage drop across a self-bias resistor, eliminating the need for a separate bias circuit. Almost 100 A of filtered copper ions have been obtained in pulse d mode, corresponding to Kappa approximately equal to 0.04. The results are interpreted by a simplified potential trough model.

  19. Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel

    SciTech Connect (OSTI)

    Lévesque, D.; Rousseau, G.; Monchalin, J.-P. [National Research Council Canada, Boucherville, QC (Canada); Wanjara, P.; Cao, X. [National Research Council Canada, Montreal, QC (Canada)

    2014-02-18T23:59:59.000Z

    The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated that the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.

  20. Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source

    SciTech Connect (OSTI)

    Vijvers, W. A. J.; Gils, C. A. J. van; Goedheer, W. J.; Meiden, H. J. van der; Veremiyenko, V. P.; Westerhout, J.; Lopes Cardozo, N. J.; Rooij, G. J. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Schram, D. C. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2008-09-15T23:59:59.000Z

    The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and hydrogen gas flow rate. Measurements of the pressure in the arc channel show that the flow is well described by Poiseuille flow and that the effective heavy particle temperature is approximately 0.8 eV. Interpretation of the measured I-V data in terms of a one-parameter model shows that the plasma production is proportional to the input power, to the square root of the hydrogen flow rate, and is independent of the channel diameter. The observed scaling shows that the dominant power loss mechanism inside the arc channel is one that scales with the effective volume of the plasma in the discharge channel. Measurements on the plasma output with Thomson scattering confirm the linear dependence of the plasma production on the input power. Extrapolation of these results shows that (without a magnetic field) an improvement in the plasma production by a factor of 10 over where it was in van Rooij et al. [Appl. Phys. Lett. 90, 121501 (2007)] should be possible.

  1. Pressure and arc voltage coupling in dc plasma torches: Identification and extraction of oscillation modes

    SciTech Connect (OSTI)

    Rat, V.; Coudert, J. F. [SPCTS UMR 6638, CNRS-University of Limoges, 123 Av. A. Thomas, 87060 Limoges Cedex (France)

    2010-08-15T23:59:59.000Z

    This work is devoted to the instabilities occurring in a plasma torch, such as those found in plasma spraying. These instabilities are responsible for a lack of reproducibility of coatings properties, especially in the case of suspension plasma spraying that is an innovative way to obtain thin coatings of submicron-sized particles. Strong Helmholtz oscillations are highlighted in the plasma flow and it is demonstrated that they overlap with different acoustic modes in addition with the more commonly admitted ''restrike'' mode, the later being due to rearcing events in the arc region. The instabilities occur in the arc voltage but it is experimentally shown in this paper that the pressure within the torch body presents the same kind of instabilities. Besides, a numerical filtering technique has been adapted to isolate the different instability components. The operating parameters of the plasma torch were varied in order to highlight their influence on the amplitude of the different modes, both for the arc voltage and the pressure.

  2. Arc plasma generator of atomic driver for steady-state negative ion source

    SciTech Connect (OSTI)

    Ivanov, A. A.; Belchenko, Yu. I.; Davydenko, V. I. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation) [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Ivanov, I. A.; Kolmogorov, V. V.; Listopad, A. A., E-mail: a.a.listopad@inp.nsk.su; Mishagin, V. V.; Shulzhenko, G. I. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)] [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Putvinsky, S. V.; Smirnov, A. [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States)] [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States)

    2014-02-15T23:59:59.000Z

    The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB{sub 6} cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

  3. Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2005-01-01T23:59:59.000Z

    Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys

  4. Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys : technical corrigendum 1

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2005-01-01T23:59:59.000Z

    Specification and qualification of welding procedures for metallic materials : Welding procedure test : Part 2: Arc welding of aluminium and its alloys : technical corrigendum 1

  5. An SF6 autoexpansion breaker; The correlation between magnetic arc control and critical current

    SciTech Connect (OSTI)

    Bernard, G.; Girard, A.; Malkin, P. (Etablissements Merlin et Gerin, 38 - Grenoble (France)); Scarpa, P. (Univ. of Liege (BE))

    1990-01-01T23:59:59.000Z

    It is possible to design SF6 autoexpansion breakers which are free from critical currents. In these devices which combine arc rotation in a magnetic field and thermal expansion of gas, critical currents can effectively occur if these effects are incorrectly created and combined. An analytic and experimental method optimizing the current at which rotation should start is presented. The study of the gas flow then ensures coupling with expansion. These investigations lead to representation of a thermal time constant directly related to interrupting capacity.

  6. Parametric Studies Of Weld Quality Of Tungsten Inert Gas Arc Welding Of Stainless Steel

    SciTech Connect (OSTI)

    Kumar Pal, Pradip; Nandi, Goutam; Ghosh, Nabendu [Mechanical Engineering Department, Jadavpur University, Kolkata-700032 (India)

    2011-01-17T23:59:59.000Z

    Effect of current and gas flow rate on quality of weld in tungsten inter gas arc welding of austenitic stainless steel has been studied in the present work through experiments and analyses. Butt welded joints have been made by using several levels of current and gas flow rate. The quality of the weld has been evaluated in terms of ultimate and breaking strengths of the welded specimens. The observed data have been interpreted, discussed and analyzed by using Grey--Taguchi methodology. Optimum parametric setting has been predicted and validated as well.

  7. Low Cost Arc Fault Detection and Protection for PV Systems: January 30, 2012 - September 30, 2013

    SciTech Connect (OSTI)

    McCalmont, S.

    2013-10-01T23:59:59.000Z

    Final report for Tigo Energy Incubator project. The specific objective of this 18-month research effort was to develop an off-the-shelf arc-fault detector. The starting point of the project was a prototype detector that was constructed using discrete components and laboratory equipment. An intermediate objective was to build a technically viable detector using programmable components in the detector circuitry. The final objective was to build a commercially viable detector by reducing the cost of the circuitry through the use of more sophisticated programmable components and higher levels of integration.

  8. Fermi arcs vs. fermi pockets in electron-doped perovskite iridates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    He, Junfeng; Hafiz, H.; Mion, Thomas R.; Hogan, T.; Dhital, C.; Chen, X.; Lin, Qisen; Hashimoto, M.; Lu, D. H.; Zhang, Y.; et al

    2015-02-23T23:59:59.000Z

    We report on an angle resolved photoemission (ARPES) study of bulk electron-doped perovskite iridate, (Sr1-xLax)?Ir?O?. Fermi surface pockets are observed with a total electron count in keeping with that expected from La substitution. Depending on the energy and polarization of the incident photons, these pockets show up in the form of disconnected “Fermi arcs”, reminiscent of those reported recently in surface electron-doped Sr?IrO?. Our observed spectral variation is consistent with the coexistence of an electronic supermodulation with structural distortion in the system.

  9. Integration of Predicted Atmospheric Contaminant Plumes into ArcView GIS

    SciTech Connect (OSTI)

    Koffman, Larry D.

    2005-10-10T23:59:59.000Z

    The Savannah River National Laboratory (SRNL) plays a key role in emergency response scenarios in which there may be a release of atmospheric chemical or radiological contamination at the DOE's Savannah River Site (SRS). Meteorologists at SRNL use a variety of tools to predict the path of the plume and levels of contamination along the path. These predictions are used to guide field teams that take sample measurements for verification. Integration of these predicted plumes as well as field measurements into existing Geographic Information System (GIS) interactive maps provides key additional information for decision makers during an emergency. In addition, having this information in GIS format facilitates sharing the information with other agencies that use GIS. In order to be useful during an emergency, an application for converting predictions or measurements into GIS format must be automated and simple to use. Thus, a key design goal in developing such applications is ease of use. Simple menu selections and intuitive forms with graphical user interfaces are used to accomplish this goal. Applications have been written to convert two different predictive code results into ArcView GIS. Meteorologists at SRNL use the Puff/Plume code, which is tied to real-time wind data, to predict the direction and spread of the atmospheric plume for early assessment. The calculated circular puffs are converted into an ArcView polygon shapefile with attributes for predicted time, dose, and radius of the puff. The meteorologists use the more sophisticated Lagrangian Particle Dispersion Model (LPDM) to predict particle dispersion and deposition. The calculational grid is brought into ArcView as a point shapefile and then interpolated to ARC GRID format using Spatial Analyst. This GRID can then be contoured into a line shapefile, which is easily shared with other agencies. The deposition grid is also automatically contoured for values that correspond to FDA Derived Intervention Levels for beef, produce, and dairy products. Decision makers at SRS routinely use these predicted plumes to direct field teams. In the case of a strong release, this information can be used to decide whether to evacuate a particular area. Having this information in GIS format may aid the decision maker because other infrastructure information can be overlaid with geographic reference.

  10. Remote reactor repair: GTA (gas tungsten Arc) weld cracking caused by entrapped helium

    SciTech Connect (OSTI)

    Kanne, W.R. Jr.

    1988-01-01T23:59:59.000Z

    A repair patch was welded to the wall of a nuclear reactor tank using remotely controlled thirty-foot long robot arms. Further repair was halted when gas tungsten arc (GTA) welds joining type 304L stainless steel patches to the 304 stainless steel wall developed toe cracks in the heat-affected zone (HAZ). The role of helium in cracking was investigated using material with entrapped helium from tritium decay. As a result of this investigation, and of an extensive array of diagnostic tests performed on reactor tank wall material, helium embrittlement was shown to be the cause of the toe cracks.

  11. Progress report on a fully automatic Gas Tungsten Arc Welding (GTAW) system development

    SciTech Connect (OSTI)

    Daumeyer, G.J. III

    1994-12-01T23:59:59.000Z

    A plan to develop a fully automatic gas tungsten arc welding (GTAW) system that will utilize a vision-sensing computer (which will provide in-process feedback control) is presently in work. Evaluations of different technological aspects and system design requirements continue. This report summaries major activities in the plan`s successful progress. The technological feasibility of producing the fully automated GTAW system has been proven. The goal of this process development project is to provide a production-ready system within the shortest reasonable time frame.

  12. quantum dynamical description of the inter-

    E-Print Network [OSTI]

    Röder, Beate

    HUMBOLDT-SPEKTRUM 3-4/2004 Nanotechnology tries to build up systems with basic functional units having even It is a strong challenge for modern research to eluci- date the functionality of systems on an atomic scale, i from the detailed understanding of everything that happens on this tiny length-scale. For example

  13. Zinc recovery by ultrasound acid leaching of double kiln treated electric arc furnace dust

    SciTech Connect (OSTI)

    Barrera Godinez, J.A.

    1989-01-01T23:59:59.000Z

    The need to convert 70,000 tons a year of electric arc furnace (EAF) dust into an environmentally safe or recyclable product has encouraged studies to reclaim zinc from this waste material. Successful characterization of a double-kiln calcine, produced from EAF dust, has shown that the calcine pellets consisted mainly of zinc oxide plates with some iron oxide particles. Preliminary leaching tests using hydrochloric and sulfuric acids indicated that this calcine is suitable for selective ultrasound leaching of zinc. A factorially designed screening test using hydrochloric acid showed that ultrasound significantly lowered iron dissolution and increased zinc dissolution, thus enhancing the selective leaching of zinc. Ultrasound, temperature, air bubbling rate and acidity increased the sulfuric acid selectivity, while fluorosilicic acid was not selective. Reactor characterization through ultrasonic field measurements led to the selection of reactor and ultrasound bath, which were utilized to enhance the selectivity of a laboratory scale sulfuric acid leaching of a double-kiln treated electric arc furnace dust. Results indicated that ultrasonic leaching of this calcine is a satisfactory technique to selectively separate zinc from iron. After further iron removal by precipitation and cementation of nickel, it was possible to electrowin zinc from the leach liquor under common industrial conditions, with current efficiencies from 86% through 92% being observed. Calcine washing showed that a substantial chloride removal is possible, but fluoride ion in the electrolyte caused deposit sticking during electrowinning.

  14. On the mechanism of operation of a cathode spot cell in a vacuum arc

    SciTech Connect (OSTI)

    Mesyats, G. A.; Petrov, A. A. [P. N. Lebedev Physical Institute, RAS, 53 Leninsky Ave., Moscow 119991 (Russian Federation); Bochkarev, M. B. [Institute of Electrophysics, UB, RAS, 106 Amundsen St., Ekaterinburg 620016 (Russian Federation); Barengolts, S. A., E-mail: sb@nsc.gpi.ru [A. M. Prokhorov General Physics Institute, RAS, 38 Vavilov St., Moscow 119991 (Russian Federation)

    2014-05-05T23:59:59.000Z

    The erosive structures formed on a tungsten cathode as a result of the motion of the cathode spot of a vacuum arc over the cathode surface have been examined. It has been found that the average mass of a cathode microprotrusion having the shape of a solidified jet is approximately equal to the mass of ions removed from the cathode within the lifetime of a cathode spot cell carrying a current of several amperes. The time of formation of a new liquid-metal jet under the action of the reactive force of the plasma ejected by the cathode spot is about 10?ns, which is comparable to the lifetime of a cell. The growth rate of a liquid-metal jet is ?10{sup 4}?cm/s. The geometric shape and size of a solidified jet are such that a new explosive emission center (spot cell) can be initiated within several nanoseconds during the interaction of the jet with the dense cathode plasma. This is the underlying mechanism of the self-sustained operation of a vacuum arc.

  15. Plasma transferred arc repair welding of the nickel-base superalloy IN-738LC

    SciTech Connect (OSTI)

    Su, C.Y.; Chou, C.P. [National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Mechanical Engineering; Wu, B.C.; Lih, W.C. [Industrial Technology Research Inst., Hsinchu (Taiwan, Province of China). Materials Research Labs.

    1997-10-01T23:59:59.000Z

    Plasma transferred arc welding (PTA) has been considered a promising process to restore worn areas of land-based gas turbine blades and vanes. The objective of this investigation was to study the effect of PTA welding on the repairing of IN-738LC superalloy components. Tensile tests were conducted on specimens welded with various combinations of parameters. Room temperature, 760 C, and 980 C were selected as tensile test temperatures. High-temperature phase transformed, during solidification, were identified by differential thermal analysis (DTA). The weld-pool shapes and microstructures of welded specimens prepared by various welding parameters were evaluated by optical metallography (OM), a scanning electron microscope (SEM) equipped with energy dispersive x-ray spectrometer (EDS), and microhardness testing. Results of this study showed that PTA welded specimens exhibited 96% nominal tensile strength of IN-738LC base materials. Specimen failure was observed predominantly in the base materials instead of in the heat-affected zone (HAZ) for gas tungsten arc weld (GTAW) repair weldments. IN-738LC is considered susceptible to weld cracking during fusion welding; however, using a low-input repair welding process (PTA), cracking susceptibility could be minimized by the optimized welding parameters.

  16. Environmental embrittlement of iron-aluminide alloy FA-129 during gas tungsten arc welding

    SciTech Connect (OSTI)

    Fasching, A.A.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States); David, S.A. [Oak Ridge National Lab, Oak Ridge, TN (United States)

    1994-12-31T23:59:59.000Z

    Iron aluminides are susceptible to hydrogen cold cracking during gastungsten arc welding (GTAW). Cracking occurs by brittle fracture in the fusion zone, which has been attributed to excessive grain growth during solidification. To further investigate hydrogen cold cracking in iron aluminides and, specifically, to study the effect of base material grain size on fusion zone cracking susceptibility, base materials of varying grain size were GTAW. The specimens for this investigation came from a production-sized vacuum arc remelt (VAR) ingot. The results of this investigation showed that changes in either the base material thermomechanical processing or the common welding parameters could not easily be used to refine the fusion zone grain size. This investigation showed that conventional GTAW produced coarse fusion zone grain structures even in fine-grained base material. The results also revealed that fracture strength decreased only slightly with a decrease in heat input, but exhibited a dramatic decrease as the water vapor content increased. in addition, the unrecrystallized base material showed the greatest susceptibility toward hydrogen cold cracking. Fracture stress versus grain size plots at different levels of water vapor were produced for iron-aluminide alloy FA-129.

  17. The determination of ranges of selected properties of an argon plasma using an electric arc of limited power

    E-Print Network [OSTI]

    Farquhar, Bannister Wells

    1963-01-01T23:59:59.000Z

    Discussion of Results VII Conclusions VIII Presentation of Data 20 24 26 33 35 References LIST OF FIGURES Figure Page Cathode Rear Plate Nozzle Flange 0 8 10 3A Collar and Cap Nozzle Schematic of Plasma Generator Energy Losses for Various... Energy Inputs Range of Plasmas Generated 0 12 15 27 28 Close-up of Arc Chamber and Plasma Jet. . . , 41 Over-all View of Plasma Generator 41 10 The Arc Chamber, Control Console and Instrumentation 42 Exploded View of Nozzle Flange, Nozzle...

  18. Contrib. Plasma Phys. 51, No. 2-3, 293 296 (2011) / DOI 10.1002/ctpp.201000061 LTE Experimental Validation in a Gas Metal Arc Welding Plasma

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    Validation in a Gas Metal Arc Welding Plasma Column F. Valensi1,2 , S. Pellerin1 , A. Boutaghane3 , K, France 7 CTAS-Air Liquide Welding, Saint Ouen l'Aum^one, 95315 Cergy-Pontoise cedex, France Received 12 Spectroscopy, Boltzmann Plot, Sola method, LTE. During gas metal arc welding (GMAW), the plasma obtained has

  19. Complex Dynamics

    E-Print Network [OSTI]

    Complex Dynamics Bernardo Da Costa, Koushik Ramachandran, Jingjing Qu, and I had a two semester learning seminar in complex analysis and potential ...

  20. Molecular dynamics study of interfacial confinement effects of aqueous NaCl brines in nanoporous carbon

    SciTech Connect (OSTI)

    Wander, M. C.F.; Shuford, K. L.

    2010-01-01T23:59:59.000Z

    In this paper, studies of aqueous electrolyte solutions in contact with a family of porous carbon geometries using classical molecular dynamics simulations are presented. These simulations provide an atomic scale depiction of ion transport dynamics in different environments to elucidate power of aqueous electrolyte supercapacitors. The electrolyte contains alkali metal and halide ions, which allow for the examination of size trends within specific geometries as well as trends in concentration. The electrode pores are modeled as planar graphite sheets and carbon nanotubes with interstices ranging from one to four nanometers. Ordered layers form parallel to the carbon surface, which facilitates focused ion motion under slightly confining conditions. As a result, the ion’s diffusivities are enhanced in the direction of the slit or pore. Further confining the system leads to decreased ion diffusivities. The ions are fully hydrated in all but the smallest slits and pores with those sizes showing increased ion pairing. There is strong evidence of charge separation perpendicular to the surface at all size scales, concentrations, and ion types, providing a useful baseline for examining differential capacitance behavior and future studies on energy storage. These systems show promise as high-power electrical energy storage devices.

  1. A Kinematic Approach To Assessing Environmental Effects: Star-Forming Galaxies in a z~0.9 SpARCS cluster using Spitzer 24um Observations

    E-Print Network [OSTI]

    Noble, A G; Muzzin, A; Wilson, G; Yee, H K C; van der Burg, R F J

    2013-01-01T23:59:59.000Z

    We present an infrared study of a z=0.872 cluster, SpARCS J161314+564930, with the primary aim of distinguishing the dynamical histories of spectroscopically confirmed star-forming members to assess the role of cluster environment. We utilize deep MIPS imaging and a mass-limited sample of 85 spectroscopic members to identify 16 24um-bright sources within the cluster, and measure their 24um star formation rates (SFRs) down to ~6 Msolar/year. Based on their line-of-sight velocities and stellar ages, MIPS cluster members appear to be an infalling population that was recently accreted from the field with minimal environmental dependency on their star formation. However, we identify a double-sequenced distribution of star-forming galaxies amongst the members, with one branch exhibiting declining specific SFRs with mass. The members along this sub-main sequence contain spectral features suggestive of passive galaxies. Using caustic diagrams, we kinematically identify these galaxies as a virialized and/or backsplash...

  2. JOURNAL DE PHYSIQUE CoZZoque C7, suppZ6ment au n07, Tome 40, JuiZZet 1979, page C7-243 THE ARC DIAMETER AND RATE OF ROTATIONff A MAGNETICALLY

    E-Print Network [OSTI]

    Boyer, Edmond

    A magnetically rotated arc heater producing a uniformly heated and highly turbulent hydrogen plasma is briefly. A magnetically rotated arc heater with hydrogen as the plasma working fluid has been developed for use in ffi 7 = 40°. mined. 2. Apparatus and procedure The arc heater (Figure 1)consisted of a non-transferred. d. c

  3. Temperature variations in an SF6-N2 mixture arc plasma A. Gleizes, M. Razafinimanana and S. Vacqui

    E-Print Network [OSTI]

    Boyer, Edmond

    1411 Temperature variations in an SF6-N2 mixture arc plasma A. Gleizes, M. Razafinimanana and S brûlant dans les mélanges SF6-N2, en fonction de l'intensité du courant. Suivant la proportion de SF6 dans courant supérieur à 50 A, les valeurs de To dans un mélange contenant 20 % de SF6 sont inférieures à

  4. 1358 IEEE TRANSACTIONS ON MAGNETICS, VOL. 40, NO. 2, MARCH 2004 Eddy-Current Effects in Circuit Breakers During Arc

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1358 IEEE TRANSACTIONS ON MAGNETICS, VOL. 40, NO. 2, MARCH 2004 Eddy-Current Effects in Circuit Abstract--This paper deals with the modeling of eddy currents generated by arc motion during opening phases in determining eddy currents in splitter plates, the second one is devoted to the calculation of eddy currents

  5. ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets

    E-Print Network [OSTI]

    Sorbom, B N; Palmer, T R; Mangiarotti, F J; Sierchio, J M; Bonoli, P; Kasten, C; Sutherland, D A; Barnard, H S; Haakonsen, C B; Goh, J; Sung, C; Whyte, D G

    2014-01-01T23:59:59.000Z

    The affordable, robust, compact (ARC) reactor conceptual design study aims to reduce the size, cost, and complexity of a combined fusion nuclear science facility (FNSF) and demonstration fusion Pilot power plant. ARC is a 270 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has rare earth barium copper oxide (REBCO) superconducting toroidal field coils, which have joints to enable disassembly. This allows the vacuum vessel to be replaced quickly, mitigating first wall survivability concerns, and permits a single device to test many vacuum vessel designs and divertor materials. The design point has a plasma fusion gain of Q_p~13.6, yet is fully non-inductive, with a modest bootstrap fraction of only ~63%. Thus ARC offers a high power gain with relatively large external control of the current profile. This highly attractive combination is enabled by the ~23 T peak field on coil with newly available REBCO superconductor technology. External cu...

  6. Theoretical study of Diesel fuel reforming by a non-thermal arc discharge A. Lebouvier1,2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Theoretical study of Diesel fuel reforming by a non-thermal arc discharge A. Lebouvier1,2 , G anti-pollution norm namely for Diesel powered vehicles. NOx (NO, NO2,...) are very irritant pollutants- nologies purge is the use of non-thermal plasma. Plasma reforming of diesel fuel and exhaust gas mix- ture

  7. 2D Axisymmetric Coupled CFD-kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel

    E-Print Network [OSTI]

    Boyer, Edmond

    1 2D Axisymmetric Coupled CFD-kinetics Modeling of a Nonthermal Arc Plasma Torch for Diesel Fuel-assisted diesel fuel reformer developed for two different applications: (i) onboard H2 production for fuel cell. In the first case, diesel fuel reacts with air while in the second case it reacts with diesel engine exhaust

  8. Exhaust gas fuel reforming of Diesel fuel by non-thermal arc discharge for NOx trap regeneration

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Exhaust gas fuel reforming of Diesel fuel by non- thermal arc discharge for NOx trap regeneration to the reforming of Diesel fuel with Diesel engine exhaust gas using a non-thermal plasma torch for NOx trap Diesel fuel reforming with hal-00617141,version1-17May2013 Author manuscript, published in "Energy

  9. Les glaciers du Haut Arc (Savoie) : caractrisation et impacts de la dcrue post-Petit Age Glaciaire

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Les glaciers du Haut Arc (Savoie) : caractérisation et impacts de la décrue post-Petit Age RECHERCHE SCIENTIFIQUE UMR 5204 tel-00011264,version1-24Dec2005 #12;1- Glacier du Baounet, S. Jobard 2004. 2- Barre de séracs sur le glacier de Charbonnel, S. Jobard 2003 3- Vue en 3D de l'extension des glaciers d

  10. Published in Powder Technology, 2005, 157, 1-3, 2-11. DUST FORMATION IN ELECTRIC ARC FURNACE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    reaction with dissolved carbon and bubbles of carbon monoxide (CO) are formed, which helps to remove other of electric arc furnace (EAF) dust shows that bubble burst at the liquid steel surface is the principal source. As in the case of the air-water system, the bubble-burst gives birth to two types of droplets: film drops and jet

  11. 1. Add street shapefile to ArcMap a. Define projection of shapefile Geographic coordinates NAD83

    E-Print Network [OSTI]

    Frank, Thomas D.

    1. Add street shapefile to ArcMap a. Define projection of shapefile ­ Geographic coordinates NAD83 address on web. Call them? c. Plastipak: wrong zip code, but still no matches. In shapefile Clinic: wrong zip code, but still no matches. In shapefile, the 1300 block of Cunningham Ave

  12. Combined electron beam and vacuum ARC melting for barrier tube shell material

    SciTech Connect (OSTI)

    Worcester, S.A.; Woods, C.R.

    1989-07-18T23:59:59.000Z

    This patent describes a process of the type wherein zirconium tetrachloride is reduced to produce a metallic zirconium sponge. The sponge is distilled to generally remove residual magnesium and magnesium chloride, and the distilled sponge is melted to produce an ingot, the improvement for making a non-crystal bar material for use in lining the interior of zirconium alloy fuel element cladding which comprises: a. forming the distilled sponge into a consumable electrode; b. melting the consumable electrode in a multiple swept beam electron furnace with a feed rate between 1 and 20 inches per hour to form an intermediate ingot; and c. vacuum arc melting the intermediate ingot to produce a homogeneous final ingot, having 50-500 ppm iron.

  13. Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65

    SciTech Connect (OSTI)

    Hashemi, S. H. [Department of Mechanical Engineering, University of Birjand, POBOX 97175-376, Birjand (Iran, Islamic Republic of); Mohammadyani, D. [Materials and Energy Research Center (MERC) POBOX 14155-4777, Tehran (Iran, Islamic Republic of)

    2011-01-17T23:59:59.000Z

    The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

  14. Method for processing aluminum spent potliner in a graphite electrode arc furnace

    DOE Patents [OSTI]

    O'Connor, William K.; Turner, Paul C.; Addison, G.W. (AJT Enterprises, Inc.)

    2002-12-24T23:59:59.000Z

    A method of processing spent aluminum pot liner containing carbon, cyanide compositions, fluorides and inorganic oxides. The spend aluminum pot liner is crushed, iron oxide is added to form an agglomerated material. The agglomerated material is melted in an electric arc furnace having the electrodes submerged in the molten material to provide a reducing environment during the furnace operation. In the reducing environment, pot liner is oxidized while the iron oxides are reduced to produce iron and a slag substantially free of cyanide compositions and fluorides. An off-gas including carbon oxides and fluorine is treated in an air pollution control system with an afterburner and a scrubber to produce NaF, water and a gas vented to the atmosphere free of cyanide compositions, fluorine, and CO.

  15. Method for processing aluminum spent potliner in a graphite electrode ARC furnace

    DOE Patents [OSTI]

    O'Connor, William K. (Lebanon, OR); Turner, Paul C. (Independence, OR); Addison, Gerald W. (St. Stephen, SC)

    2002-12-24T23:59:59.000Z

    A method of processing spent aluminum pot liner containing carbon, cyanide compositions, fluorides and inorganic oxides. The spent aluminum pot liner is crushed iron oxide is added to form an agglomerated material. The agglomerated material is melted in an electric arc furnace having the electrodes submerged in the molten material to provide a reducing environment during the furnace operation. In the reducing environment, pot liner is oxidized while the iron oxides are reduced to produce iron and a slag substantially free of cyanide compositions and fluorides. An off-gas including carbon oxides and fluorine is treated in an air pollution control system with an afterburner and a scrubber to produce NaF, water and a gas vented to the atmosphere free of cyanide compositions, fluorine and CO.

  16. Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder Metallurgy Produced Titanium Alloys

    SciTech Connect (OSTI)

    Muth, Thomas R [ORNL; Yamamoto, Yukinori [ORNL; Frederick, David Alan [ORNL; Contescu, Cristian I [ORNL; Chen, Wei [ORNL; Lim, Yong Chae [ORNL; Peter, William H [ORNL; Feng, Zhili [ORNL

    2013-01-01T23:59:59.000Z

    ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

  17. A two-dimensional thermomechanical simulation of a gas metal arc welding process

    SciTech Connect (OSTI)

    Ortega, A.R.

    1990-08-01T23:59:59.000Z

    A low heat input gas metal arc (GMA) weld overlay process is being investigated as a possible means to repair Savannah River nuclear reactor tanks in the event cracks are detected in the reactor walls. Two-dimensional thermomechanical simulations of a GMA welding process were performed using the finite element code ABAQUS to assist in the design of the upcoming weld experiments on helium-charged specimens. The thermal model correlated well with existing test data, i.e., fusion zone depth and thermocouple data. In addition, numerical results revealed that after cool-down the final deformation of the workpiece was qualitatively similar to the shape observed experimentally. Based on these analyses, conservative recommendations were made for the workpiece dimensions, weld pass spacing, and thermomechanical boundary conditions to ensure the experiments would be as representative as possible of welding on the reactor walls. 12 refs., 13 figs.

  18. Theoretical analysis of weld pool behavior in the pulsed current Gas Tungsten Arc Welding (GTAW) process

    SciTech Connect (OSTI)

    Tsai, C.L. (Ohio State Univ., Columbus (United States)); Hou, C.A. (Howard Univ., Washington, DC (United States))

    1988-02-01T23:59:59.000Z

    A general three-dimensional, closed-form welding heat-flow solution, which is capable of analyzing thermal behavior of the weldment in its transient state and/or under time-dependent power change during welding, is presented. The analytical model utilizes the finite heat source theory with a Gaussian distribution and also considers the effects of finite plate thickness. The numerical values of the solution are calculated using the computational schemes on a minicomputer. In this paper the welding parameters of the pulsed current Gas Tungsten Arc Welding (GTAW) were studied using the solution. Two sets of pulsation parameters were analyzed and their sensitivity to the heat input control were evaluated.

  19. High energy arcing fault fires in switchgear equipment : a literature review.

    SciTech Connect (OSTI)

    Nowlen, Steven Patrick; Brown, Jason W.; Wyant, Francis John

    2008-10-01T23:59:59.000Z

    In power generating plants, switchgear provide a means to isolate and de-energize specific electrical components and buses in order to clear downstream faults, perform routine maintenance, and replace necessary electrical equipment. These protective devices may be categorized by the insulating medium, such as air or oil, and are typically specified by voltage classes, i.e. low, medium, and high voltage. Given their high energy content, catastrophic failure of switchgear by means of a high energy arcing fault (HEAF) may occur. An incident such as this may lead to an explosion and fire within the switchgear, directly impact adjacent components, and possibly render dependent electrical equipment inoperable. Historically, HEAF events have been poorly documented and discussed in little detail. Recent incidents involving switchgear components at nuclear power plants, however, were scrupulously investigated. The phenomena itself is only understood on a very elementary level from preliminary experiments and theories; though many have argued that these early experiments were inaccurate due to primitive instrumentation or poorly justified methodologies and thus require re-evaluation. Within the past two decades, however, there has been a resurgence of research that analyzes previous work and modern technology. Developing a greater understanding of the HEAF phenomena, in particular the affects on switchgear equipment and other associated switching components, would allow power generating industries to minimize and possibly prevent future occurrences, thereby reducing costs associated with repair and downtime. This report presents the findings of a literature review focused on arc fault studies for electrical switching equipment. The specific objective of this review was to assess the availability of the types of information needed to support development of improved treatment methods in fire Probabilistic Risk Assessment (PRA) for nuclear power plant applications.

  20. Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace

    SciTech Connect (OSTI)

    Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

    2014-01-01T23:59:59.000Z

    This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electric arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.

  1. Onsite recycling of electric arc furnace dust: The Jorgensen Steel Facility

    SciTech Connect (OSTI)

    Licis, I.J. [Environmental Protection Agency, Cincinnati, OH (United States); Bermark, R.C. [Washington State Dept. of Ecology, Olympia, WA (United States)

    1995-10-01T23:59:59.000Z

    The steel-making industry produces a large amount of Electric Arc Furnace (EAF) dust as part of normal production. This waste is listed as KO61, defined as {open_quotes}emission control dust/sludge from the primary production of steel in electric arc furnaces{close_quotes} under 40 CFR 261.32. A glass making technology called Ek Glassification{trademark} (hereafter called {open_quotes}the Process{close_quotes}) has been developed by Roger B. Ek and Associates, Inc. (hereafter called {open_quotes}the Developer{close_quotes}) to recycle EAF dust and convert it, along with other byproducts of the steel-making industry, into marketable commodities. This Process was evaluated under the Waste Reduction Innovative Technology Evaluation (WRITE) Program. The project was designed and conducted in cooperation with the Washington State Department of Environmental Quality, the Process Developer and the host test site, the Earle M. Jorgensen (EMJ) Steel Company of Seattle, Washington. Test personnel for EPA were supplied by SAIC Inc., on contract to EPA. The overall objectives of the project were to conduct a pilot scale evaluation of the Process, investigate if toxic metals are leached from the products (such as colored glass and glass-ceramics; ceramic glazes, colorants, and fillers; roofing granules and sand-blasting grit; and materials for Portland cement production). Three glass recipes (Glass I, II, and III) were designed by the developer for potential use at EMJ. The EPA portion was focused on determining the toxic metals concentrations of the Glass II recipe, evaluating the P2 impact of using this Process in comparison to traditional methods of waste treatment and disposal, and assessing the economics of both.

  2. Texture analysis on the fluence map to evaluate the degree of modulation for volumetric modulated arc therapy

    SciTech Connect (OSTI)

    Park, So-Yeon [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Kim, Il Han [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Department of Radiation Oncology, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Ye, Sung-Joon [Department of Radiation Oncology, Seoul National University Hospital, Seoul 110-744, (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744 (Korea, Republic of); Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 433-270 (Korea, Republic of); Carlson, Joel [Biomedical Research Institute, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 433-270 (Korea, Republic of); and others

    2014-11-01T23:59:59.000Z

    Purpose: Texture analysis on fluence maps was performed to evaluate the degree of modulation for volumetric modulated arc therapy (VMAT) plans. Methods: A total of six textural features including angular second moment, inverse difference moment, contrast, variance, correlation, and entropy were calculated for fluence maps generated from 20 prostate and 20 head and neck VMAT plans. For each of the textural features, particular displacement distances (d) of 1, 5, and 10 were adopted. To investigate the deliverability of each VMAT plan, gamma passing rates of pretreatment quality assurance, and differences in modulating parameters such as multileaf collimator (MLC) positions, gantry angles, and monitor units at each control point between VMAT plans and dynamic log files registered by the Linac control system during delivery were acquired. Furthermore, differences between the original VMAT plan and the plan reconstructed from the dynamic log files were also investigated. To test the performance of the textural features as indicators for the modulation degree of VMAT plans, Spearman’s rank correlation coefficients (r{sub s}) with the plan deliverability were calculated. For comparison purposes, conventional modulation indices for VMAT including the modulation complexity score for VMAT, leaf travel modulation complexity score, and modulation index supporting station parameter optimized radiation therapy (MI{sub SPORT}) were calculated, and their correlations were analyzed in the same way. Results: There was no particular textural feature which always showed superior correlations with every type of plan deliverability. Considering the results comprehensively, contrast (d = 1) and variance (d = 1) generally showed considerable correlations with every type of plan deliverability. These textural features always showed higher correlations to the plan deliverability than did the conventional modulation indices, except in the case of modulating parameter differences. The r{sub s} values of contrast to the global gamma passing rates with criteria of 2%/2 mm, 2%/1 mm, and 1%/2 mm were 0.536, 0.473, and 0.718, respectively. The respective values for variance were 0.551, 0.481, and 0.688. In the case of local gamma passing rates, the r{sub s} values of contrast were 0.547, 0.578, and 0.620, respectively, and those of variance were 0.519, 0.527, and 0.569. All of the r{sub s} values in those cases were statistically significant (p < 0.003). In the cases of global and local gamma passing rates, MI{sub SPORT} showed the highest correlations among the conventional modulation indices. For global passing rates, r{sub s} values of MI{sub SPORT} were ?0.420, ?0.330, and ?0.632, respectively, and those for local passing rates were ?0.455, ?0.490 and ?0.502. The values of r{sub s} of contrast, variance, and MI{sub SPORT} with the MLC errors were ?0.863, ?0.828, and 0.795, respectively, all with statistical significances (p < 0.001). The correlations with statistical significances between variance and dose-volumetric differences were observed more frequently than the others. Conclusions: The contrast (d = 1) and variance (d = 1) calculated from fluence maps of VMAT plans showed considerable correlations with the plan deliverability, indicating their potential use as indicators for assessing the degree of modulation of VMAT plans. Both contrast and variance consistently showed better performance than the conventional modulation indices for VMAT.

  3. Introduction Linear Dynamics

    E-Print Network [OSTI]

    Zeghib, Abdelghani

    Introduction Results Linear Dynamics Lorentz Dynamics Actions of discrete groups on stationary Piccione) Geodeycos Meeting, Lyon, 28-30 April 2010 Abdelghani Zeghib Dynamics on Lorentz manifolds #12;Introduction Results Linear Dynamics Lorentz Dynamics Motivations and questions Examples 1 Introduction

  4. Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies

    SciTech Connect (OSTI)

    Dr. Xiaodi Huang; Dr. J. Y. Hwang

    2005-03-28T23:59:59.000Z

    Steel is a basic material broadly used by perhaps every industry and individual. It is critical to our nation's economy and national security. Unfortunately, the American steel industry is losing competitiveness in the world steel production field. There is an urgent need to develop the next generation of steelmaking technology for the American steel industry. Direct steelmaking through the combination of microwave, electric arc, and exothermal heating is a revolutionary change from current steelmaking technology. This technology can produce molten steel directly from a shippable agglomerate, consisting of iron oxide fines, powdered coal, and ground limestone. This technology is projected to eliminate many current intermediate steelmaking steps including coking, pellet sintering, blast furnace (BF) ironmaking, and basic oxygen furnace (BOF) steelmaking. This technology has the potential to (a) save up to 45% of the energy consumed by conventional steelmaking; (b) dramatically reduce the emission of CO{sub 2}, SO{sub 2}, NO{sub x}, VOCs, fine particulates, and air toxics; (c) substantially reduce waste and emission control costs; (d) greatly lower capital cost; and (e) considerably reduce steel production costs. This technology is based on the unique capability of microwaves to rapidly heat steelmaking raw materials to elevated temperature, then rapidly reduce iron oxides to metal by volumetric heating. Microwave heating, augmented with electric arc and exothermal reactions, is capable of producing molten steel. This technology has the components necessary to establish the ''future'' domestic steel industry as a technology leader with a strong economically competitive position in world markets. The project goals were to assess the utilization of a new steelmaking technology for its potential to achieve better overall energy efficiency, minimize pollutants and wastes, lower capital and operating costs, and increase the competitiveness of the U.S. steel industry. The objectives associated with this goal were to (a) generate a solid base of technical, marketing, economic, and policy data, (b) develop energy, environmental, and economic targets, (c) more definitively assess opportunities and barriers, (d) accumulate knowledge and experience for defining direction for the next phase of development, and (e) promote learning and training of students.

  5. Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2*

    E-Print Network [OSTI]

    Hallett, William L.H.

    Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2 model. Processes of Particle Pyrolysis Pyrolysis (or devolatilization) is the thermal breakdown

  6. Web: http://dust.ess.uci.edu/prp/prp_ans/prp_ans.pdf NSF Arctic Natural Sciences (ANS) Proposal ARC-0714088 Submitted: December 8, 2006

    E-Print Network [OSTI]

    Zender, Charles

    Web: http://dust.ess.uci.edu/prp/prp_ans/prp_ans.pdf NSF Arctic Natural Sciences (ANS) Proposal ARC dissemination of LGGE snow measurements as http://dust.ess.uci.edu/snw. Identified IPY sub-disciplines as Snow

  7. The noble gas and carbon systematics of divergent, convergent and strike-slip plate boundaries : examples from the Reykjanes Ridge, Central American Arc and North Anatolian Fault Zone

    E-Print Network [OSTI]

    Leeuw, Goverdina Anna Maria de

    2007-01-01T23:59:59.000Z

    arc. Contrib. Mineral. Petrol. , 105, 369–380. Carr, M. J. ,to degassing. J. Petrol. , 36, 1633–1646. Dixon, J. E. ,and solubility models. J. Petrol. , 36, 1607–1631. Doremus,

  8. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED MELDING PROCESSES IN RELATION TO THE ARC CURRENT DENSITY A Thesis by ROBIN KENT DEVORE Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT...

  9. Mouvements actuels des blocs tectoniques dans l'arc Btico-Rifain partir des mesures GPS entre 1999 et 2005

    E-Print Network [OSTI]

    Demouchy, Sylvie

    sciences, université Abdelmalek-Essaâdi, M'hannech II, B.P. 2121, 93002 Tétouan, Maroc b UMR5562/DTP, école Mohammadia d'ingénieurs, B.P. 765, avenue Ibn-Sina, Rabat, Maroc d Department of Earth structuraux de l'arc Bético-Rifain (Maroc et Ibérie). Les mouvements sont asymétriques dans la région d

  10. Tribological performance of hybrid filtered arc-magnetron coatings - Part I: Coating deposition process and basic coating properties characterization

    SciTech Connect (OSTI)

    Gorokhovsky, Vladimir; Bowman, C.; Gannon, Paul E.; VanVorous, D.; Voevodin, A. A.; Rutkowski, A.; Muratore, C.; Smith, Richard J.; Kayani, Asghar N.; Gelles, David S.; Shutthanandan, V.; Trusov, B. G.

    2006-12-04T23:59:59.000Z

    Aircraft propulsion applications require low-friction and wear resistant surfaces that operate under high contact loads in severe environments. Recent research on supertough and low friction nanocomposite coatings produced with hybrid plasma deposition processes was demonstrated to have a high potential for such demanding applications. However, industrially scalable hybrid plasma technologies are needed for their commercial realization. The Large area Filtered Arc Deposition (LAFAD) process provides atomically smooth coatings at high deposition rates over large surface areas. The LAFAD technology allows functionally graded, multilayer, super-lattice and nanocomposite architectures of multi-elemental coatings via electro-magnetic mixing of two plasma flows composed of different metal ion vapors. Further advancement can be realized through a combinatorial process using a hybrid filtered arc-magnetron deposition system. In the present study, multilayer and nanostructured TiCrCN/TiCr +TiBC composite cermet coatings were deposited by the hybrid filtered arc-magnetron process. Filtered plasma streams from arc evaporated Ti and Cr targets, and two unbalanced magnetron sputtered B4C targets, were directed to the substrates in the presence of reactive gases. A multiphase nanocomposite coating architecture was designed to provide the optimal combination of corrosion and wear resistance of advanced steels (Pyrowear 675) used in aerospace bearing and gear applications. Coatings were characterized using SEM/EDS, XPS and RBS for morphology and chemistry, XRD and TEM for structural analyses, wafer curvature and nanoindentation for stress and mechanical properties, and Rockwell and scratch indentions for adhesion. Coating properties were evaluated for a variety of coating architectures. Thermodynamic modeling was used for estimation of phase composition of the top TiBC coating segment. Correlations between coating chemistry, structure and mechanical properties are discussed.

  11. Compositional Control of Surface Oxides on Metal Alloys using Photons: Dynamic Simulations and Experiments

    SciTech Connect (OSTI)

    Chang, C.; Sankaranarayanan, S; Ruzmetov, D; Engelhard, M; Kaxiras, E; Ramanathan, S

    2010-01-01T23:59:59.000Z

    We report on the ability to modify the structure and composition of ultrathin oxides grown on Ni and Ni-Al alloy surfaces at room temperature utilizing photon illumination. We find that the nickel-oxide formation is enhanced in the case of oxidation under photo-excitation. The enhanced oxidation kinetics of nickel in 5% Ni-Al alloy is corroborated by experimental and simulation studies of natural and photon-assisted oxide growth on pure Ni(100) surfaces. In case of pure Ni substrates, combined x-ray photoelectron spectroscopy analysis, and atomic force microscope current mapping support the deterministic role of the structure of nickel passive-oxide films on their nanoscale corrosion resistance. Atomistic simulations involving dynamic charge transfer predict that the applied electric field overcomes the activation-energy barrier for ionic migration, leading to enhanced oxygen incorporation into the oxide, enabling us to tune the mixed-oxide composition at atomic length scales. Atomic scale control of ultrathin oxide structure and morphology in the case of pure substrates as well as compositional tuning of complex oxide in the case of alloys leads to excellent passivity as verified from potentiodynamic polarization experiments.

  12. The Molecular Structure of a Phosphatidylserine Bilayer Determined by Scattering and Molecular Dynamics Simulations

    SciTech Connect (OSTI)

    Pan, Jianjun [University of South Florida, Tampa (USF)] [University of South Florida, Tampa (USF); Cheng, Xiaolin [ORNL] [ORNL; Monticelli, Luca [Institut National de la Santé et de la Recherche Médicale (INSERM) and INTS, France] [Institut National de la Santé et de la Recherche Médicale (INSERM) and INTS, France; Heberle, Frederick A [ORNL] [ORNL; Kucerka, Norbert [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,] [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,; Tieleman, D. Peter [University of Calgary, ALberta, Canada] [University of Calgary, ALberta, Canada; Katsaras, John [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Phosphatidylserine (PS) lipids play essential roles in biological processes, including enzyme activation and apoptosis. We report on the molecular structure and atomic scale interactions of a fluid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylserine (POPS). A scattering density profile model, aided by molecular dynamics (MD) simulations, was developed to jointly refine different contrast small-angle neutron and X-ray scattering data, which yielded a lipid area of 62.7 A2 at 25 C. MD simulations with POPS lipid area constrained at different values were also performed using all-atom and aliphatic united-atom models. The optimal simulated bilayer was obtained using a model-free comparison approach. Examination of the simulated bilayer, which agrees best with the experimental scattering data, reveals a preferential interaction between Na+ ions and the terminal serine and phosphate moieties. Long-range inter-lipid interactions were identified, primarily between the positively charged ammonium, and the negatively charged carboxylic and phosphate oxygens. The area compressibility modulus KA of the POPS bilayer was derived by quantifying lipid area as a function of surface tension from area-constrained MD simulations. It was found that POPS bilayers possess a much larger KA than that of neutral phosphatidylcholine lipid bilayers. We propose that the unique molecular features of POPS bilayers may play an important role in certain physiological functions.

  13. Final Scientific/Technical Report "Arc Tube Coating System for Color Consistency"

    SciTech Connect (OSTI)

    Buelow, Roger; Jenson, Chris; Kazenski, Keith

    2013-03-21T23:59:59.000Z

    DOE has enabled the use of coating materials using low cost application methods on light sources to positively affect the output of those sources. The coatings and light source combinations have shown increased lumen output of LED fixtures (1.5%-2.0%), LED arrays (1.4%) and LED powered remote phosphor systems â?? Philips L-Prize lamp (0.9%). We have also demonstrated lifetime enhancements (3000 hrs vs 8000 hrs) and shifting to higher CRI (51 to 65) in metal halide high intensity discharge lamps with metal oxide coatings. The coatings on LEDs and LED products are significant as the market is moving increasingly more towards LED technology. Enhancements in LED performance are demonstrated in this work through the use of available materials and low cost application processes. EFOI used low refractive index fluoropolymers and low cost dipping processes for application of the material to surfaces related to light transmission of LEDs and LED products. Materials included Teflon AF, an amorphous fluorinated polymer and fluorinated acrylic monomers. The DOE SSL Roadmap sets goals for LED performance moving into the future. EFOIâ??s coating technology is a means to shift the performance curve for LEDs. This is not limited to one type of LED, but is relevant across LED technologies. The metal halide work included the use of sol-gel solutions resulting in silicon dioxide and titanium dioxide coatings on the quartz substrates of the metal halide arc tubes. The coatings were applied using low cost dipping processes.

  14. Establishing an optimized patient-specific verification program for volumetric modulated arc therapy

    SciTech Connect (OSTI)

    Serna, Alfredo, E-mail: alfredo.serna@carm.es [Department of Medical Physics, Hospital Universitario Santa Lucía, Cartagena (Spain); Mata, Fernando; Puchades, Vicente [Department of Medical Physics, Hospital Universitario Santa Lucía, Cartagena (Spain)

    2013-10-01T23:59:59.000Z

    Quality assurance (QA) of volumetric modulated arc therapy (VMAT) increases the workload significantly. We compared the results from 4 verification methods to establish an efficient VMAT QA. Planning for VMAT treatments was carried out for 40 consecutive patients. Pretreatment verifications were carried out with ion chamber array Physikalish-Technische Werkstätten (PTW729), electronic portal dosimetry (EPID), ion chamber measurements, and independent dose calculation with Diamond program. 2D analyses were made using the gamma analysis (3 mm distance to agreement and 3% dose difference relative to maximum, 10% dose threshold). Average point dose difference calculated by Eclipse relative to ion chamber measurements and Diamond were 0.1%±0.9% and 0.6%±2.2%, respectively. Average pass rate for PTW729 was 99.2%±1.9% and 98.3%±1.3% for EPID. The total required time (linac occupancy time given in parentheses) for each QA method was: PTW729 43.5 minutes (26.5 minutes), EPID 14.5 minutes (2.5 minutes), ion chamber 34.5 minutes (26.5 minutes), and Diamond 12.0 minutes (0 minute). The results were consistent and allowed us to establish an optimized protocol, considering safety and accuracy as well as workload, consisting of 2 verification methods: EPID 2D analysis and independent dose calculation.

  15. Effect of the Collimator Angle on Dosimetric Verification of the Volumetric Modulated Arc Therapy

    E-Print Network [OSTI]

    Kim, Yong Ho; Kim, Won Taek; Kim, Dong Won; Ki, Yongkan; Lee, Juhye; Bae, Jinsuk; Park, Dahl

    2015-01-01T23:59:59.000Z

    Collimator angle is usually rotated when planning volumetric modulated arc therapy (VMAT) due to the leakage of radiation between multi-leaf collimator (MLC) leaves. We studied the effect of the collimator angles on the results of dosimetric verification of the VMAT plans for head and neck patients. We studied VMAT plans for 10 head and neck patients. We made 2 sets of VMAT plans for each patient. Each set was composed of 10 plans with collimator angles of 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 degrees. Plans in the first set were optimized individually and plans in the second set shared the 30 degree collimator angle optimization. Two sets of plans were verified using the 2-dimensional ion chamber array MatriXX (IBA Dosimetry, Germany). The comparison between the calculation and measurements were made by the $\\gamma$-index analysis. The $\\gamma$-index (2\\%/2 mm) and (3\\%/3 mm) passing rates had negative correlations with the collimator angle. Maximum difference between $\\gamma$-index (3\\%/3 mm) passing rates o...

  16. Stability of very-high pressure arc discharges against perturbations of the electron temperature

    SciTech Connect (OSTI)

    Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

    2012-04-01T23:59:59.000Z

    We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

  17. Optical Sensors for Post Combustion Control in Electric Arc Furnace Steelmaking (TRP 9851)

    SciTech Connect (OSTI)

    Sarah W. Allendorf; David K. Ottesen; Robert W. Green; Donald R. Hardesty; Robert Kolarik; Howard Goodfellow; Euan Evenson; Marshall Khan; Ovidiu Negru; Michel Bonin; Soren Jensen

    2003-12-31T23:59:59.000Z

    Working in collaboration with Stantec Global Technologies, Process Metrix Corporation, and The Timken Company, Sandia National Laboratories constructed and evaluated a novel, laser-based off-gas sensor at the electric arc furnace facility of Timken's Faircrest Steel Plant (Canton, Ohio). The sensor is based on a mid-infrared tunable diode laser (TDL), and measures the concentration and temperature of specific gas species present in the off-gas emanating from the EAF. The laser beam is transmitted through the gas stream at the fourth hole of the EAF, and provides a real-time, in situ measurement that can be used for process optimization. Two sets of field tests were performed in parallel with Stantec's extractive probe off-gas system, and the tests confirm the TDL sensor's operation and applicability for electric steel making. The sensor measures real-time, in situ line-of-sight carbon monoxide (CO) concentrations between 5% and 35% CO, and measures off-gas temperature in the range of 1400 to 1900 K. In order to achieve commercial-ready status, future work is required to extend the sensor for simultaneous CO and CO{sub 2} concentration measurements. In addition, long-term endurance tests including process optimization must be completed.

  18. Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009)

    SciTech Connect (OSTI)

    Dr. Gordon A. Irons

    2004-03-31T23:59:59.000Z

    Nitrogen is difficult to remove in electric arc furnace (EAF) steelmaking, requiring the use of more energy in the oxygen steelmaking route to produce low-nitrogen steel. The objective of this work was to determine if the injection of directly reduced iron (DRI) fines into EAFs could reduce the nitrogen content by creating fine carbon monoxide bubbles that rinse nitrogen from the steel. The proposed work included physical and chemical characterization of DRI fines, pilot-scale injection into steel, and mathematical modeling to aid in scale-up of the process. Unfortunately, the pilot-scale injections were unsuccessful, but some full-scale data was obtained. Therefore, the original objectives were met, and presented in the form of recommendations to EAF steelmakers regarding: (1) The best composition and size of DRI fines to use; (2) The amount of DRI fines required to achieve a specific reduction in nitrogen content in the steel; and (3) The injection conditions. This information may be used by steelmakers in techno-economic assessments of the cost of reducing nitrogen with this technology.

  19. Vaccum Gas Tungsten Arc Welding, phase 1. Technical report, October 1993-March 1995

    SciTech Connect (OSTI)

    Weeks, J.L.; Krotz, P.D.; Todd, D.T.; Liaw, Y.K.

    1995-03-01T23:59:59.000Z

    This two year program will investigate Vacuum Gas Tungsten Arc Welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. VGTAW appears to offer a significant improvement in weldability because of the clean environment and lower heat input needed. The overall objective of the program is to develop the VGTAW technology and implement it into a manufacturing environment that will result in lower cost, better quality and higher reliability aerospace components for the space shuttle and other NASA space systems. Phase 1 of this program was aimed at demonstrating the process`s ability to weld normally difficult-to-weld materials. Phase 2 will focus on further evaluation, a hardware demonstration and a plan to implement VGTAW technology into a manufacturing environment. During Phase 1, the following tasks were performed: (1) Task 11000 Facility Modification - an existing vacuum chamber was modified and adapted to a GTAW power supply; (2) Task 12000 Materials Selection - four difficult-to-weld materials typically used in the construction of aerospace hardware were chosen for study; (3) Task 13000 VGTAW Experiments - welding experiments were conducted under vacuum using the hollow tungsten electrode and evaluation. As a result of this effort, two materials, NARloy Z and Incoloy 903, were downselected for further characterization in Phase 2; and (4) Task 13100 Aluminum-Lithium Weld Studies - this task was added to the original work statement to investigate the effects of vacuum welding and weld pool vibration on aluminum-lithium alloys.

  20. atomic-scale contact potential: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with both trans and gauche conformations bound to the gold clusters at top, bridge and hollow bonding sites. Comparing our results with the experimental data of Hihath et al....

  1. atom-scale molecular interactions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with both trans and gauche conformations bound to the gold clusters at top, bridge and hollow bonding sites. Comparing our results with the experimental data of Hihath et al....

  2. X-ray Laser Used to Produce Movies of Atomic-scale Motion | U...

    Office of Science (SC) Website

    with open access in the Supplementary Information External link at the publication web site. Highlight Categories Program: BES, MSE, SUF PerformerFacility: DOE Laboratory,...

  3. Atomic-Scale Chemical, Physical and Electronic Properties of the Subsurface Hydride of Palladium

    SciTech Connect (OSTI)

    Weiss, Paul

    2014-01-20T23:59:59.000Z

    We employed low-temperature, extreme-high vacuum scanning tunneling microscopy (STM) to investigate the roles of subsurface hydride (H) and deuteride (D) in the surface reconstruction and surface reactivity of Pd{110}. Specifically, we gained the ability to tailor the surface structure of Pd{110} both by preparation method and by deposition of deuterium from the gas phase. We observed thiophene at low coverage on Pd{110} to determine its adsorption orientation and electronic structure through scanning tunneling spectroscopy (STS) – namely, conductance spectroscopy and differential conductance imaging. We developed the methods necessary to coadsorb D adatoms with thiophene molecules, and to induce the reaction of individual molecules with predefined subsurface H or D features. In the case of Pd{110}, we found a much more pronounced effect from subsurface D, as it is influenced by the surface directionality. These experiments facilitate an understanding of the role of surface and subsurface H and D in heterogeneous catalytic processes, specifically in the hydrodesulfuization (HDS) of thiophene, an important and ubiquitous component found to be detrimental to petroleum refining.

  4. Atomic-Scale Study of Calcite Nucleation in Calcium Oxide Rmy Besson*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    :UMR 5307, LGF, F-42023 Saint-Etienne ABSTRACT In spite of its wide use, the properties of the CaO/CaCO3 the elastic properties of coherent CaO/CaCO3 layered systems. This reveals the special role played by the (111 (CaO) and calcite (CaCO3), connected through the reaction CaO + CO2 CaCO3 and already well

  5. Atomic-scale characterization of germanium isotopic multilayers by atom probe tomography

    SciTech Connect (OSTI)

    Shimizu, Y.; Takamizawa, H.; Toyama, T.; Inoue, K.; Nagai, Y. [Oarai Center, Institute for Materials Research, Tohoku University, 2145-2 Narita, Oarai, Ibaraki 311-1313 (Japan); Kawamura, Y.; Uematsu, M.; Itoh, K. M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Haller, E. E. [University of California at Berkeley and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2013-01-14T23:59:59.000Z

    We report comparison of the interfacial sharpness characterization of germanium (Ge) isotopic multilayers between laser-assisted atom probe tomography (APT) and secondary ion mass spectrometry (SIMS). An alternating stack of 8-nm-thick naturally available Ge layers and 8-nm-thick isotopically enriched {sup 70}Ge layers was prepared on a Ge(100) substrate by molecular beam epitaxy. The APT mass spectra consist of clearly resolved peaks of five stable Ge isotopes ({sup 70}Ge, {sup 72}Ge, {sup 73}Ge, {sup 74}Ge, and {sup 76}Ge). The degree of intermixing at the interfaces between adjacent layers was determined by APT to be around 0.8 {+-} 0.1 nm which was much sharper than that obtained by SIMS.

  6. Atomic-scale and three-dimensional transmission electron microscopy of nanoparticle morphology

    E-Print Network [OSTI]

    Leary, Rowan Kendall

    2015-02-03T23:59:59.000Z

    nanoparticles with reactive concave surfaces. A compressed sensing-electron tomography (CS-ET) approach. Nano Letters, 11(11): 4666-4673, 2011. Peer reviewed conference proceedings R. Leary, Z. Saghi, P.A. Midgley, and D.J. Holland. Compressed Sensing Electron... algorithms, precision in component fabrication and stability of electrical components that AC optics yielded performance improvements in practice. First generation AC optics have addressed the major limiting aberration, third-order spherical aberration. In a...

  7. Role of support-nanoalloy interactions in the atomic-scale structural...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interaction influences the catalytic activity of a ternary nanoalloy (platinum-nickel-cobalt) particles on three different supports: carbon, silica and titania. The...

  8. A Unified Invariant Formulation, by Frames, from General Relativity to the Atomic Scale

    E-Print Network [OSTI]

    Shmuel Kaniel

    2010-05-11T23:59:59.000Z

    The aim of this article is the formulation of the basic laws of Physics by frames, i.e. quadruples of exterior differential one forms. The basic operator is a modification of the Hodge-de Rham Laplacian d*d*+*d*d, where * is the hyperbolic star. In this article it is modified depending on the frame. The modified * is invariant w.r. to any diffeomorphism. Consequently, the modified Laplavian is invariant. The field equation developed in this article is a complete alternative to the field equation of General Relativity in vacuum. The frame-field equation yields a derivation of Newtonian (Einstein) law of attraction without recourse to the geodesic postulate. Coulomb law is also derived. Invariant formulation of Maxwell equations is exhibited. Then first order linear approximation is considered. It is used to derive invariant formulation of Schroedinger equation (classical and relativistic) and Dirac equation all of which are linear. The lhs of the field equation, defined on a four dimensional manifold, is the same for all bodies. Thus hopefully, it may set the foundation for a field theory. The interaction of the particles has to be worked out. The basic equation of this article is motivated by the Einstein equation in nonempty space.

  9. A Unified Invariant Formulation, by Frames, from General Relativity to the Atomic Scale

    E-Print Network [OSTI]

    Kaniel, Shmuel

    2009-01-01T23:59:59.000Z

    The aim of this article is the formulation of the basic laws of Physics by frames, i.e. quadruples of exterior differential one forms. The basic operator is a modification of the Hodge-de Rham Laplacian d*d*+*d*d, where * is the hyperbolic star. In this article it is modified depending on the frame. The modified * is invariant w.r. to any diffeomorphism. Consequently, the modified Laplavian is invariant. The field equation developed in this article is a complete alternative to the field equation of General Relativity in vacuum. The frame-field equation yields a derivation of Newtonian (Einstein) law of attraction without recourse to the geodesic postulate. Coulomb law is also derived. Invariant formulation of Maxwell equations is exhibited. Then first order linear approximation is considered. It is used to derive invariant formulation of Schroedinger equation (classical and relativistic) and Dirac equation all of which are linear. The lhs of the field equation, defined on a four dimensional manifold, is the s...

  10. THE ATOMIC-SCALE CHARACTERIZATION OF DEFECTS ON CLEAVED VANADIUM AND MOLYBDENUM OXIDE SURFACES USING STM

    E-Print Network [OSTI]

    Rohrer, Gregory S.

    USING STM GREGORY S. ROHRER AND RICHARD L. SMITH Carnegie Mellon University Department of Materials in the vanadyl 0 position to be identified on cleaved V20 5(001) surfaces. Mo 180 52(100) and Mo 80 23) surface plane and create white contrast parallel to [010]. These standards for contrast identification can

  11. Time Resolution Dependence of Information Measures for Spiking Neurons: Atoms, Scaling, and Universality

    E-Print Network [OSTI]

    Sarah E. Marzen; Michael R. DeWeese; James P. Crutchfield

    2015-04-18T23:59:59.000Z

    The mutual information between stimulus and spike-train response is commonly used to monitor neural coding efficiency, but neuronal computation broadly conceived requires more refined and targeted information measures of input-output joint processes. A first step towards that larger goal is to develop information measures for individual output processes, including information generation (entropy rate), stored information (statistical complexity), predictable information (excess entropy), and active information accumulation (bound information rate). We calculate these for spike trains generated by a variety of noise-driven integrate-and-fire neurons as a function of time resolution and for alternating renewal processes. We show that their time-resolution dependence reveals coarse-grained structural properties of interspike interval statistics; e.g., $\\tau$-entropy rates that diverge less quickly than the firing rate indicate interspike interval correlations. We also find evidence that the excess entropy and regularized statistical complexity of different types of integrate-and-fire neurons are universal in the continuous-time limit in the sense that they do not depend on mechanism details. This suggests a surprising simplicity in the spike trains generated by these model neurons. Interestingly, neurons with gamma-distributed ISIs and neurons whose spike trains are alternating renewal processes do not fall into the same universality class. These results lead to two conclusions. First, the dependence of information measures on time resolution reveals mechanistic details about spike train generation. Second, information measures can be used as model selection tools for analyzing spike train processes.

  12. Atomic-Scale Simulation of Colloidal Nanoparticle Forces and Kristen A. Fichthorn

    E-Print Network [OSTI]

    Bjørnstad, Ottar Nordal

    areas in dye-sensitized solar cells, where their aggregation and interfacial structure can influence cells. Nanoparticles also figure prominently in solar-cell technologies, for example as efficient light

  13. On the thermodynamic efficiency of a multiferroic thermomagnetic generator: From bulk to atomic scale

    E-Print Network [OSTI]

    Sandoval, Samuel M.

    2014-01-01T23:59:59.000Z

    18:1116, 1947. [Tes89] Nikola Tesla. “Thermo Magnetic Motor:Electromagnetic Induction Nikola Tesla postulated the first

  14. atomic-scale intracellular water: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Small structural changes in molecular surfaces can evoke large changes in the contact energy of hydrated surfaces; surface hydration and the energetics of water displacement are a...

  15. Resolution Limits of Electron-Beam Lithography toward the Atomic Scale

    E-Print Network [OSTI]

    Zhang, Lihua

    We investigated electron-beam lithography with an aberration-corrected scanning transmission electron microscope. We achieved 2 nm isolated feature size and 5 nm half-pitch in hydrogen silsesquioxane resist. We also analyzed ...

  16. Nanotechnology Nanotechnology comprises measurement, design, modeling and fabrication of materials and systems at the atomic scale.

    E-Print Network [OSTI]

    Glowinski, Roland

    Nanotechnology Nanotechnology comprises measurement, design, modeling and fabrication of materials are able to customize their education by specializing in areas such as nanotechnology, computational

  17. Atomic-Scale Observations Aid Mesoscale Catalyst Design | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational ManagementDemand ModuleNationalAtomic,

  18. Simulations of Kinetic Events at the Atomic Scale | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo »UsageSecretary of EnergyFocus GroupSherrell R.Chemical Kinetic

  19. Tomographic study of atomic-scale redistribution of platinum during the

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesisAppliances Tips:Harper receives cybersilicidation

  20. Measurement of Transient Atomic-scale Displacements in Thin Films with

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from a NewCuneo Matthew1, 20121 H( 7

  1. Introduction to Dynamic Distributed

    E-Print Network [OSTI]

    Roma "La Sapienza", Università di

    Introduction to Dynamic Distributed SystemsSystems #12;Outline Introduction Churn Building Applications in Dynamic Distributed Systems RegistersRegisters Eventual Leader election Connectivity in Dynamic Distributed Systems #12;Dynamic Distributed Systems: Context & Motivations Advent of Complex Distributed

  2. Flavor Dynamics

    E-Print Network [OSTI]

    Michael Murray; for the BRAHMS Collaboration

    2007-10-24T23:59:59.000Z

    The purpose of BRAHMS is to survey the dynamics of relativistic heavy ion (as well as pp and d-A) collisions over a very wide range of rapidity and transverse momentum. The sum of these data may give us a glimpse of the initial state of the system, its transverse and longitudinal evolution and how the nature of the system changes with time. Here I will concentrate on the origin and dynamics of the light flavors, i.e. the creation and transport of the up, down and strange quarks. The results presented here are certainly not the end of the story. It is my hope that in a few years new detectors will reveal the rapidity dependence of the charm and bottom quarks.

  3. Volumetric Modulated Arc Therapy: Planning and Evaluation for Prostate Cancer Cases

    SciTech Connect (OSTI)

    Zhang, Pengpeng, E-mail: zhangp@mskcc.or [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Happersett, Laura; Hunt, Margie; Jackson, Andrew [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zelefsky, Michael [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Mageras, Gig [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2010-04-15T23:59:59.000Z

    Purpose: To develop an optimization method using volumetric modulated arc therapy (VMAT) and evaluate VMAT plans relative to the standard intensity-modulated radiotherapy (IMRT) approach in prostate cancer. Methods and Materials: A single gantry rotation was modeled using 177 equispaced beams. Multileaf collimator apertures and dose rates were optimized with respect to gantry angle subject to dose-volume-based objectives. Our VMAT implementation used conjugate gradient descent to optimize dose rate, and stochastic sampling to find optimal multileaf collimator leaf positions. A treatment planning study of 11 prostate cancer patients with a prescription dose of 86.4 Gy was performed to compare VMAT with a standard five-field IMRT approach. Plan evaluation statistics included the percentage of planning target volume (PTV) receiving 95% of prescribed dose (V95), dose to 95% of PTV (D95), mean PTV dose, tumor control probability, and dosimetric endpoints of normal organs, whereas monitor unit (MU) and delivery time were used to assess delivery efficiency. Results: Patient-averaged PTV V95, D95, mean dose, and tumor control probability in VMAT plans were 96%, 82.6 Gy, 88.5 Gy, and 0.920, respectively, vs. 97%, 84.0 Gy, 88.9 Gy, and 0.929 in IMRT plans. All critical structure dose requirements were met. The VMAT plans presented better rectal wall sparing, with a reduction of 1.5% in normal tissue complication probability. An advantage of VMAT plans was that the average number of MUs (290 MU) was less than for IMRT plans (642 MU). Conclusion: The VMAT technique can reduce beam on time by up to 55% while maintaining dosimetric quality comparable to that of the standard IMRT approach.

  4. Tunable, self-powered integrated arc plasma-melter vitrification system for waste treatment and resource recovery

    DOE Patents [OSTI]

    Titus, Charles H. (Newtown Square, PA); Cohn, Daniel R. (Chestnuthill, MA); Surma, Jeffrey E. (Kennewick, WA)

    1998-01-01T23:59:59.000Z

    The present invention provides a relatively compact self-powered, tunable waste conversion system and apparatus which has the advantage of highly robust operation which provides complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The system provides the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or by an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In the preferred embodiment of the invention, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The preferred configuration of this embodiment of the invention utilizes two arc plasma electrodes with an elongated chamber for the molten pool such that the molten pool is capable of providing conducting paths between electrodes. The apparatus may additionally be employed with reduced or without further use of the gases generated by the conversion process. The apparatus may be employed as a self-powered or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production.

  5. Dosimetric comparison of volumetric modulated Arc therapy, step-and-shoot, and sliding window IMRT for prostate cancer

    SciTech Connect (OSTI)

    Schnell, Erich; De La Fuente Herman, Tania; Young, Julie; Hildebrand, Kim; Algan, Ozer; Syzek, Elizabeth; Herman, Terence; Ahmad, Salahuddin [Department of Radiation Oncology, University of Oklahoma Health Sciences Center 800 N.E. 10th St., OKCC L100, Oklahoma City, OK 73104 (United States)

    2012-10-23T23:59:59.000Z

    This study aims to evaluate treatment plans generated by Step-and-Shoot (SS), Sliding Window (SW) and Volumetric Modulated Arc Therapy (VMAT) in order to assess the differences in dose volume histograms of planning target volume (PTV) and organs at risk (OAR), conformity indices, radiobiological evaluations, and plan quality for prostate cancer cases. Six prostate cancer patients treated in our center were selected for this retrospective study. Treatment plans were generated with Eclipse version 8.9 using 10 MV photon beams. For VMAT, Varian Rapid Arc with 1 or 2 arcs, and for SS and SW IMRT, 7-9 fields were used. Each plan had three PTVs with prescription doses of 81, 59.4, and 45 Gy to prostate, to prostate and lymph nodes, and to pelvis, respectively. Doses to PTV and OAR and the conformal indices (COIN) were compared among three techniques. The equivalent uniform dose (EUD), tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated and compared. The mean doses to the PTV prostate on average were 83 Gy and the percent differences of mean dose among all techniques were below 0.28. For bladder and rectum, the percent differences of mean dose among all techniques were below 2.2. The COIN did not favour any particular delivery method over the other. The TCP was higher with SS and SW for four patients and higher with VMAT for two patients. The NTCP for the rectum was the lowest with VMAT in five out of the six patients. The results show similar target coverage in general.

  6. Photoelectron Emission from Metal Surfaces Induced by VUV-emission of Filament Driven Hydrogen Arc Discharge Plasma

    E-Print Network [OSTI]

    Laulainen, J; Koivisto, H; Komppula, J; Tarvainen, O

    2015-01-01T23:59:59.000Z

    Photoelectron emission measurements have been performed using a filament-driven multi-cusp arc discharge volume production H^- ion source (LIISA). It has been found that photoelectron currents obtained with Al, Cu, Mo, Ta and stainless steel (SAE 304) are on the same order of magnitude. The photoelectron currents depend linearly on the discharge power. It is shown experimentally that photoelectron emission is significant only in the short wavelength range of hydrogen spectrum due to the energy dependence of the quantum efficiency. It is estimated from the measured data that the maximum photoelectron flux from plasma chamber walls is on the order of 1 A per kW of discharge power.

  7. The modelling of irradiation-enhanced phosphorus segregation in neutron irradiated reactor pressure vessel submerged-arc welds

    SciTech Connect (OSTI)

    Druce, S.G.; English, C.A.; Foreman, A.J.E.; McElroy, R.J.; Vatter, I.A. [AEA Technology, Didcot (United Kingdom). Harwell Lab.; Bolton, C.J.; Buswell, J.T.; Jones, R.B. [Nuclear Electric, Berkeley (United Kingdom). Berkeley Technology Centre

    1996-12-31T23:59:59.000Z

    Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such ad dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies. The critical parameters in the models have been adjusted to give consistency with the available reference data, and predictions have been made of the dependence of segregation on a number of variables.

  8. Dynamic Analysis of Wind Turbine Planetary Gears Using an Extended Harmonic Balance Approach: Preprint

    SciTech Connect (OSTI)

    Guo, Y.; Keller, J.; Parker, R. G.

    2012-06-01T23:59:59.000Z

    The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.

  9. Entry and exit sets in the dynamics of area preserving Henon map

    E-Print Network [OSTI]

    E. Petrisor

    2002-09-23T23:59:59.000Z

    In this paper we study dynamical properties of the area preserving Henon map, as a discrete version of open Hamiltonian systems, that can exhibit chaotic scattering. Exploiting its geometric properties we locate the exit and entry sets, i.e. regions through which any forward, respectively backward, unbounded orbit escapes to infinity. In order to get the boundaries of these sets we prove that the right branch of the unstable manifold of the hyperbolic fixed point is the graph of a function, which is the uniform limit of a sequence of functions whose graphs are arcs of the symmetry lines of the Henon map, as a reversible map.

  10. Biological-based optimization and volumetric modulated arc therapy delivery for stereotactic body radiation therapy

    SciTech Connect (OSTI)

    Diot, Quentin; Kavanagh, Brian; Timmerman, Robert; Miften, Moyed [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States); Department of Radiation Oncology, University of Texas Southwestern Medical School, Dallas, Texas 75390 (United States); Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

    2012-01-15T23:59:59.000Z

    Purpose: To describe biological-based optimization and Monte Carlo (MC) dose calculation-based treatment planning for volumetric modulated arc therapy (VMAT) delivery of stereotactic body radiation therapy (SBRT) in lung, liver, and prostate patients. Methods: Optimization strategies and VMAT planning parameters using a biological-based optimization MC planning system were analyzed for 24 SBRT patients. Patients received a median dose of 45 Gy [range, 34-54 Gy] for lung tumors in 1-5 fxs and a median dose of 52 Gy [range, 48-60 Gy] for liver tumors in 3-6 fxs. Prostate patients received a fractional dose of 10 Gy in 5 fxs. Biological-cost functions were used for plan optimization, and its dosimetric quality was evaluated using the conformity index (CI), the conformation number (CN), the ratio of the volume receiving 50% of the prescription dose over the planning target volume (Rx/PTV50). The quality and efficiency of the delivery were assessed according to measured quality assurance (QA) passing rates and delivery times. For each disease site, one patient was replanned using physical cost function and compared to the corresponding biological plan. Results: Median CI, CN, and Rx/PTV50 for all 24 patients were 1.13 (1.02-1.28), 0.79 (0.70-0.88), and 5.3 (3.1-10.8), respectively. The median delivery rate for all patients was 410 MU/min with a maximum possible rate of 480 MU/min (85%). Median QA passing rate was 96.7%, and it did not significantly vary with the tumor site. Conclusions: VMAT delivery of SBRT plans optimized using biological-motivated cost-functions result in highly conformal dose distributions. Plans offer shorter treatment-time benefits and provide efficient dose delivery without compromising the plan conformity for tumors in the prostate, lung, and liver, thereby improving patient comfort and clinical throughput. The short delivery times minimize the risk of patient setup and intrafraction motion errors often associated with long SBRT treatment delivery times.

  11. Postoperative Intensity-Modulated Arc Therapy for Cervical and Endometrial Cancer: A Prospective Report on Toxicity

    SciTech Connect (OSTI)

    Vandecasteele, Katrien, E-mail: Katrien.Vandecasteele@uzgent.be [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium); Tummers, Philippe; Makar, Amin [Department of Gynecologic Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Gynecologic Oncology, Ghent University Hospital, Ghent (Belgium); Eijkeren, Marc van [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium); Delrue, Louke [Department of Radiology, Ghent University Hospital, Ghent (Belgium)] [Department of Radiology, Ghent University Hospital, Ghent (Belgium); Denys, Hannelore [Department of Medical Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Medical Oncology, Ghent University Hospital, Ghent (Belgium); Lambert, Bieke [Department of Nuclear Medicine, Ghent University Hospital, Ghent (Belgium)] [Department of Nuclear Medicine, Ghent University Hospital, Ghent (Belgium); Beerens, Anne-Sophie [Department of Pathology, Ghent University Hospital, Ghent (Belgium)] [Department of Pathology, Ghent University Hospital, Ghent (Belgium); Van den Broecke, Rudy [Department of Gynecologic Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Gynecologic Oncology, Ghent University Hospital, Ghent (Belgium); Lambein, Kathleen [Department of Pathology, Ghent University Hospital, Ghent (Belgium)] [Department of Pathology, Ghent University Hospital, Ghent (Belgium); Fonteyne, Valerie; De Meerleer, Gert [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium)] [Department of Radiation Oncology, Ghent University Hospital, Ghent (Belgium)

    2012-10-01T23:59:59.000Z

    Purpose: To report on toxicity after postoperative intensity-modulated arc therapy (IMAT) for cervical (CC) and endometrial cancer (EC). Methods and Materials: Twenty-four CC and 41 EC patients were treated with postoperative IMAT. If indicated, para-aortic lymph node irradiation (preventive or when affected, PALN) and/or concomitant cisplatin (40 mg/m Superscript-Two , weekly) was administered. The prescribed dose for IMAT was 45 Gy (CC, 25 fractions) and 46 Gy (EC, 23 fractions), followed by a brachytherapeutic boost if possible. Radiation-related toxicity was assessed prospectively. The effect of concomitant cisplatin and PALN irradiation was evaluated. Results: Regarding acute toxicity (n = 65), Grade 3 and 2 acute gastrointestinal toxicity was observed in zero and 63% of patients (79% CC, 54% EC), respectively. Grade 3 and 2 acute genitourinary toxicity was observed in 1% and 18% of patients, respectively. Grade 2 (21%) and 3 (12%) hematologic toxicity (n = 41) occurred only in CC patients. Seventeen percent of CC patients and 2% of EC patients experienced Grade 2 fatigue and skin toxicity, respectively. Adding cisplatin led to an increase in Grade >2 nausea (57% vs. 9%; p = 0.01), Grade 2 nocturia (24% vs. 4%; p = 0.03), Grade {>=}2 hematologic toxicity (38% vs. nil, p = 0.003), Grade {>=}2 leukopenia (33% vs. nil, p = 0.009), and a strong trend toward more fatigue (14% vs. 2%; p = 0.05). Para-aortic lymph node irradiation led to an increase of Grade 2 nocturia (31% vs. 4%, p = 0.008) and a strong trend toward more Grade >2 nausea (44% vs. 18%; p = 0.052). Regarding late toxicity (n = 45), no Grade 3 or 4 late toxicity occurred. Grade 2 gastrointestinal toxicity, genitourinary toxicity, and fatigue occurred in 4%, 9%, and 1% of patients. Neither concomitant cisplatin nor PALN irradiation increased late toxicity rates. Conclusions: Postoperative IMAT for EC or CC is associated with low acute and late toxicity. Concomitant chemotherapy and PALN irradiation influences acute but not late toxicity.

  12. In-situ Study of Dynamic Phenomena at Metal Nanosolder Interfaces Using Aberration Corrected Scanning Transmission Electron Microcopy.

    SciTech Connect (OSTI)

    Lu, Ping

    2014-10-01T23:59:59.000Z

    Controlling metallic nanoparticle (NP) interactions plays a vital role in the development of new joining techniques (nanosolder) that bond at lower processing temperatures but remain viable at higher temperatures. The pr imary objective of this project is t o develop a fundamental understanding of the actual reaction processes, associated atomic mechanisms, and the resulting microstructure that occur during thermally - driven bond formation concerning metal - metal nano - scale (<50nm) interfaces. In this LDRD pr oject, we have studied metallic NPs interaction at the elevated temperatures by combining in - situ transmission electron microscopy (TEM ) using an aberration - corrected scanning transmission electron microscope (AC - STEM) and atomic - scale modeling such as m olecular dynamic (MD) simulations. Various metallic NPs such as Ag, Cu and Au are synthesized by chemical routines. Numerous in - situ e xperiments were carried out with focus of the research on study of Ag - Cu system. For the first time, using in - situ STEM he ating experiments , we directly observed t he formation of a 3 - dimensional (3 - D) epitaxial Cu - Ag core - shell nanoparticle during the thermal interaction of Cu and Ag NPs at elevated temperatures (150 - 300 o C). The reaction takes place at temperatures as low as 150 o C and was only observed when care was taken to circumvent the effects of electron beam irradiation during STEM imaging. Atomic - scale modeling verified that the Cu - Ag core - shell structure is energetically favored, and indicated that this phenomenon is a nano - scale effect related to the large surface - to - volume ratio of the NPs. The observation potentially can be used for developing new nanosolder technology that uses Ag shell as the %22glue%22 that stic ks the particles of Cu together. The LDRD has led to several journal publications and numerous conference presentations, and a TA. In addition, we have developed new TEM characterization techniques and phase - field modeling tools that can be used for future materials research at Sandia. Acknowledgeme nts This work was supported by the Laboratory Directed Research and Development (LDRD) program of Sandia National Laboratories. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidia ry of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  13. Hyperbolic Dynamics Todd Fisher

    E-Print Network [OSTI]

    Fisher, Todd

    Hyperbolic Dynamics Todd Fisher tfisher@math.umd.edu Department of Mathematics University of Maryland, College Park Hyperbolic Dynamics ­ p. 1/3 #12;What is a dynamical system? Phase space X, elements possible states Hyperbolic Dynamics ­ p. 2/3 #12;What is a dynamical system? Phase space X, elements

  14. Compositional Tuning of Ultrathin Surface Oxides on Metal and Alloy Substrates Using Photons: Dynamic Simulations and Experiments

    SciTech Connect (OSTI)

    Chang, Chia-Lin; Sankaranarayanan, Subramanian; Ruzmetov, Dmitry; Engelhard, Mark H.; Kaxiras, Efthimios; Ramanathan, Shriram

    2010-02-02T23:59:59.000Z

    Oxide synthesis with controlled functional properties is desirable for a plethora of applications but is elusive due to oxide growth kinetics. Here, we report on the ability to modify the structure and composition of ultra-thin oxides grown on Ni-Al alloy surfaces at room temperature utilizing photon illumination. Atomistic simulations that take into account dynamic charge transfer predict that the electric field produced across an oxide film in photon-assisted synthesis overcomes the activation energy barrier for ionic migration, leading to enhanced oxidation kinetics and oxygen incorporation into the oxide, enabling us to control the oxide composition at atomic length scales. Experiments (near-edge x-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy) indicate that the native oxide on 5%Ni-Al alloy is primarily composed of aluminum oxide with no nickel oxide whereas the photon-assisted oxide comprises of both aluminum oxide and nickel oxide. The ability to tune the composition at the atomic scale of the ultra-thin oxide films leads to excellent passivity as verified from polarization experiments.

  15. Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter

    SciTech Connect (OSTI)

    Byon, Eungsun; Kim, Jong-Kuk; Kwon, Sik-Chol; Anders, Andre

    2003-12-01T23:59:59.000Z

    The effect of ion mass and charge state on plasma transport through a 90{sup o}-curved magnetic filter is experimentally investigated using a pulsed cathodic arc source. Graphite, copper, and tungsten were selected as test materials. The filter was a bent copper coil biased via the voltage drop across a low-ohm, ''self-bias'' resistor. Ion transport is accomplished via a guiding electric field, whose potential forms a ''trough'' shaped by the magnetic guiding field of the filter coil. Evaluation was done by measuring the filtered ion current and determination of the particle system coefficient, which can be defined as the ratio of filter ion current, divided by the mean ion charge state, to the arc current. It was found that the ion current and particle system coefficient decreased as the mass-to-charge ratio of ions increased. This result can be qualitatively interpreted by a very simply model of ion transport that is based on compensation of the centrifugal force by the electric force associated with the guiding potential trough.

  16. Direct Plan Comparison of RapidArc and CyberKnife for Spine Stereotactic Body Radiation Therapy

    E-Print Network [OSTI]

    Choi, Young Eun; Song, Si Yeol; Choi, Eun Kyung; Ahn, Seung Do; Cho, Byungchul

    2015-01-01T23:59:59.000Z

    We compared the treatment planning performance of RapidArc (RA) vs. CyberKnife (CK) for spinal stereotactic body radiation therapy (SBRT). Ten patients with spinal lesions who had been treated with CK were re-planned with RA, which consisted of two complete arcs. Computed tomography (CT) and volumetric dose data of CK, generated using the Multiplan (Accuray) treatment planning system (TPS) and the Ray-Trace algorithm, were imported to Varian Eclipse TPS in Dicom format, and the data were compared with the RA plan using analytical anisotropic algorithm (AAA) dose calculation. The optimized dose priorities for both CK and RA plans were similar for all patients. The highest priority was to provide enough dose coverage to the planned target volume (PTV) while limiting the maximum dose to the spinal cord. Plan quality was evaluated with respect to PTV coverage, conformity index (CI), high-dose spillage, intermediate-dose spillage (R50% and D2cm), and maximum dose to the spinal cord, which are criteria recommended ...

  17. Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal

    SciTech Connect (OSTI)

    Liu Fei; Zhang Zhaodong; Liu Liming, E-mail: liulm@dlut.edu.cn

    2012-07-15T23:59:59.000Z

    Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80-100 {mu}m between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn{sub 2}, Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg-Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: Black-Right-Pointing-Pointer Mg alloy AZ31B and Al alloy 6061 are welded successfully. Black-Right-Pointing-Pointer Zinc wire is employed as a filler metal to form the alloyed welding seam. Black-Right-Pointing-Pointer An alloyed welding seam is benefit for improving of the joint tensile strength.

  18. Recycling of rubber tires in electric arc furnace steelmaking: simultaneous combustion of metallurgical coke and rubber tyres blends

    SciTech Connect (OSTI)

    Magdalena Zaharia; Veena Sahajwalla; Byong-Chul Kim; Rita Khanna; N. Saha-Chaudhury; Paul O'Kane; Jonathan Dicker; Catherine Skidmore; David Knights [University of New South Wales, Sydney, NSW (Australia). School of Materials Science and Engineering

    2009-05-15T23:59:59.000Z

    The present study investigates the effect of addition of waste rubber tires on the combustion behavior of its blends with coke for carbon injection in electric arc furnace steelmaking. Waste rubber tires were mixed in different proportions with metallurgical coke (MC) (10:90, 20:80, 30:70) for combustion and pyrolysis at 1473 K in a drop tube furnace (DTF) and thermogravimetric analyzer (TGA), respectively. Under experimental conditions most of the rubber blends indicated higher combustion efficiencies compared to those of the constituent coke. In the early stage of combustion the weight loss rate of the blends is much faster compared to that of the raw coke due to the higher volatile yield of rubber. The presence of rubber in the blends may have had an impact upon the structure during the release and combustion of their high volatile matter (VM) and hence increased char burnout. Measurements of micropore surface area and bulk density of the chars collected after combustion support the higher combustion efficiency of the blends in comparison to coke alone. The surface morphology of the 30% rubber blend revealed pores in the residual char that might be attributed to volatile evolution during high temperature reaction in oxygen atmosphere. Physical properties and VM appear to have a major effect upon the measured combustion efficiency of rubber blends. The study demonstrates that waste rubber tires can be successfully co-injected with metallurgical coke in electric arc furnace steelmaking process to provide additional energy from combustion. 44 refs., 11 figs., 2 tabs.

  19. A Spectroscopic Redshift for the Cl0024+16 Multiple Arc System: Implications for the Central Mass Distribution

    E-Print Network [OSTI]

    Tom Broadhurst; Xiaosheng Huang; Brenda Frye; Richard Ellis

    1999-02-23T23:59:59.000Z

    We present a spectroscopic redshift of z=1.675 for the well-known multiply lensed system of arcs seen in the z=0.39 cluster Cl0024+16. In contrast to earlier work, we find that the lensed images are accurately reproduced by a projected mass distribution which traces the locations of the brightest cluster ellipticals, suggesting that the most significant minima of the cluster potential are not fully erased. The averaged mass profile is shallow and consistent with predictions of recent numerical simulations. The source redshift enables us to determine an enclosed cluster mass of M(<100kpc/h)=1.11+/-0.03 x 10^{14}M_{\\odot}/h and a mass-to-light ratio of M/L_B(<100kpc/h)=320h(M/L_B)_{\\odot}, after correction for passive stellar evolution. The arc spectrum contains many ionized absorption lines and closely resembles that of the local Wolf-Rayet galaxy NGC4217. Our lens model predicts a high magnification (~20) for each image and identifies a new pair of multiple images at a predicted redshift of z=1.3.

  20. Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties

    SciTech Connect (OSTI)

    Penik, M.A. Jr. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1997-04-01T23:59:59.000Z

    Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

  1. The 8 O'Clock Arc: A Serendipitous Discovery of a Strongly Lensed Lyman Break Galaxy in the SDSS DR4 Imaging Data

    SciTech Connect (OSTI)

    Allam, Sahar S.; /Fermilab /Wyoming U.; Tucker, Douglas L.; Lin, Huan; Diehl, H.Thomas; Annis, James; Buckley-Geer, Elizabeth J.; /Fermilab; Frieman, Joshua A.; /Fermilab

    2006-11-01T23:59:59.000Z

    We report on the serendipitous discovery of the brightest Lyman Break Galaxy (LBG) currently known, a galaxy at z = 2.73 that is being strongly lensed by the z = 0.38 Luminous Red Galaxy (LRG) SDSS J002240.91+143110.4. The arc of this gravitational lens system, which we have dubbed the ''8 o'clock arc'' due to its time of discovery, was initially identified in the imaging data of the Sloan Digital Sky Survey Data Release 4 (SDSS DR4); followup observations on the Astrophysical Research Consortium (ARC) 3.5m telescope at Apache Point Observatory confirmed the lensing nature of this system and led to the identification of the arc's spectrum as that of an LBG. The arc has a spectrum and a redshift remarkably similar to those of the previous record-holder for brightest LBG (MS 1512-cB58, a.k.a ''cB58''), but, with an estimated total magnitude of (g,r,i) = (20.0,19.2,19.0) and surface brightness of ({mu}{sub g}, {mu}{sub r}, {mu}{sub i}) = (23.3, 22.5, 22.3) mag arcsec{sup -2}, the 8 o'clock arc is thrice as bright. The 8 o'clock arc, which consists of three lensed images of the LBG, is 162{sup o}(9.6'') long and has a length-to-width ratio of 6:1. A fourth image of the LBG--a counter-image--can also be identified in the ARC 3.5m g-band images. A simple lens model for the system assuming a singular isothermal ellipsoid potential yields an Einstein radius of {theta}{sub Ein} = 2.91'' {+-} 0.14'', a total mass for the lensing LRG (within the 10.6 {+-} 0.5 h{sup -1} kpc enclosed by the lensed images) of 1.04 x 10{sup 12} h{sup -1} M{sub {circle_dot}}, and a magnification factor for the LBG of 12.3{sub -3.6}{sup +15}. The LBG itself is intrinsically quite luminous ({approx} 6 x L{sub *}) and shows indications of massive recent star formation, perhaps as high as 160 h{sup -1} M{sub {circle_dot}} yr{sup -1}.

  2. The Microscopic Linear Dynamics

    E-Print Network [OSTI]

    Penny, Will

    The Microscopic Brain Will Penny Linear Dynamics Exponentials Matrix Exponential Eigendecomposition Dynamical Modes Nodes State Space Saddles Oscillations Spirals Centres Offsets Retinal Circuit Nullclines Stability Spiking Neurons Fitzhugh-Nagumo Nonlinear Dynamics Linearization Nonlinear Oscillation Excitable

  3. Protein Dynamics and Biocatalysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Protein Dynamics and Biocatalysis Protein Dynamics and Biocatalysis 1998 Annual Report Grand Challenge Projects biocatalysis.gif A model of the Michaelis complex for the TEM-1...

  4. Comparative dosimetric and radiobiological assessment among a nonstandard RapidArc, standard RapidArc, classical intensity-modulated radiotherapy, and 3D brachytherapy for the treatment of the vaginal vault in patients affected by gynecologic cancer

    SciTech Connect (OSTI)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Caivano, Rocchina [Service of Medical Physics, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Fiorentino, Alba [U.O. of Radiotherapy, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Califano, Giorgia [Service of Medical Physics, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Barbieri, Viviana; Sanpaolo, Piero; Castaldo, Giovanni [U.O. of Radiotherapy, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Benassi, Marcello [Service of Medical Physics, Scientific Institute of Tumors of Romagna IRST, Meldola (Italy); Fusco, Vincenzo [U.O. of Radiotherapy, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy)

    2012-01-01T23:59:59.000Z

    To evaluate a nonstandard RapidArc (RA) modality as alternative to high-dose-rate brachytherapy (HDR-BRT) or IMRT treatments of the vaginal vault in patients with gynecological cancer (GC). Nonstandard (with vaginal applicator) and standard (without vaginal applicator) RapidArc plans for 27 women with GC were developed to compare with HDR-BRT and IMRT. Dosimetric and radiobiological comparison were performed by means of dose-volume histogram and equivalent uniform dose (EUD) for planning target volume (PTV) and organs at risk (OARs). In addition, the integral dose and the overall treatment times were evaluated. RA, as well as IMRT, results in a high uniform dose on PTV compared with HDR-BRT. However, the average of EUD for HDR-BRT was significantly higher than those with RA and IMRT. With respect to the OARs, standard RA was equivalent of IMRT but inferior to HDR-BRT. Furthermore, nonstandard RA was comparable with IMRT for bladder and sigmoid and better than HDR-BRT for the rectum because of a significant reduction of d{sub 2cc}, d{sub 1cc}, and d{sub max} (p < 0.01). Integral doses were always higher than HDR-BRT, although the values were very low. Delivery times were about the same and more than double for HDR-BRT compared with IMRT and RA, respectively. In conclusion, the boost of dose on vaginal vault in patients affected by GC delivered by a nonstandard RA technique was a reasonable alternative to the conventional HDR-BRT because of a reduction of delivery time and rectal dose at substantial comparable doses for the bladder and sigmoid. However HDR-BRT provides better performance in terms of PTV coverage as evidenced by a greater EUD.

  5. Type B Accident Investigation of the April 8, 2003, Electrical Arc Blast at the Foster Wheeler Environmental Corporation TRU Waste Processing Facility, Oak Ridge, Tennessee

    Broader source: Energy.gov [DOE]

    At approximately 0330 hours on April 8, 2003, a phase-to-phase arc blast occurred in the boiler electrical control panel at the Foster Wheeler Environmental Corporation (FWENC) Transuranic (TRU) Waste Processing Facility. The boiler was providing steam for the evaporator and was reportedly operating at about 10% of its capacity.

  6. Department of Computer Science University of North Carolina at Chapel Hill March 2005 Electric arcs and lightning effects are ubiquitous in science

    E-Print Network [OSTI]

    Whitton, Mary C.

    Department of Computer Science University of North Carolina at Chapel Hill March 2005 Background Electric arcs and lightning effects are ubiquitous in science fiction and fantasy films. Fromthegenesisof discharge have a long history as a dramatic tool in the visual effects industry. Despite the popularity

  7. Plasma diagnostics in gas metal arc welding by optical emission spectroscopy This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Plasma diagnostics in gas metal arc welding by optical emission spectroscopy This article has been welding by optical emission spectroscopy F Valensi1,2 , S Pellerin1 , A Boutaghane3 , K Dzierzega4 de Bourges), BP 4043, 18028 Bourges cedex, France 7 CTAS-Air Liquide Welding, Saint Ouen l

  8. Protrusion of fore-arc mantle serpentinites together with HP and UHP rocks along major strike-slip fault zones, Northern Subduction Complex, Hispaniola

    E-Print Network [OSTI]

    -slip fault zones, Northern Subduction Complex, Hispaniola Benoit-Michel SAUMUR (bsaum014@uottawa.ca), Kéiko H in the Northern Subduction Complex of Hispaniola. We discuss the origins of the serpentinites and implications and inliers exposing Cretaceous to mid-Eocene basement in Northern Hispaniola are highlighted. Arc volcanic

  9. Wood density in forests of Brazil's `arc of deforestation': Implications for biomass and flux of carbon from land-use change in Amazonia

    E-Print Network [OSTI]

    Camara, Gilberto

    Wood density in forests of Brazil's `arc of deforestation': Implications for biomass and flux of deforestation'', where most of the carbon flux from land-use change takes place. This paper presents new wood of deforestation, using locally collected species weighted by their volume in large local inventories. Mean wood

  10. Registration General Info. Day 1 Sched. Day 2 Sched. Keynote Speaker Bios. Symposia Matrix Symposia Abstracts 14th Annual ARC Conference

    E-Print Network [OSTI]

    Papalambros, Panos

    Eaton Corporation Peter J. Savagian Director of Hybrid Powertrain Engineering GM Powertrain, General Motors Corporation Rani Finstad Global PT Director Manufacturing Design Simulation & Support, General Motors Corporation Question and Answer Session 11:45 - 1:15pm Lunch 14th Annual ARC Conference - Day 1

  11. Journal of the Geological Society, London, Vol. 163, 2006, pp. 363373. Printed in Great Britain. Late Neoproterozoic proto-arc ocean crust in the Dariv Range, Western Mongolia

    E-Print Network [OSTI]

    Brouwer, Fraukje M.

    . 363 Late Neoproterozoic proto-arc ocean crust in the Dariv Range, Western Mongolia: a supra Institute of Geology and Mineral Resources, Mongolian Academy of Sciences, Ulanbaatar, Mongolia 6 Vening is exposed in the Dariv Range (western Mongolia), which contains intermediate to acidic lavas and sheeted

  12. Experimental and theoretical study of exhaust gas fuel reforming of Diesel fuel by a non-thermal arc discharge for syngas production

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -thermal arc discharge for syngas production A. Lebouvier1,2 , F. Fresnet2 , F. Fabry1 , V. Boch2 , V. Rohani1% and a conversion rate of 95% have been reached which correspond to a syngas dry molar fraction of 25%. For the most and promote H2O and CO2 production. Keywords: Plasma reformer, syngas, diesel fuel reforming, NOx trap. 1

  13. Dynamics of Motivations

    E-Print Network [OSTI]

    Knoll, Jörn

    Dynamics of Resonances GSI, 18.05.2005 Motivations Thermal Equilibrium -N- vectormesons Di-leptons Towards dynamics Conserving -functional Gradient ap- proximation Quantum Kinetic Equation Summary Dynamics. Voskresensky1,3 1GSI 2Kurchatov Inst. (Moscow) 3Moscow Ins. for Physics and Engineering #12;Dynamics

  14. Dynamics on Lorentz manifolds

    E-Print Network [OSTI]

    Zeghib, Abdelghani

    Dynamics on Lorentz manifolds Abdelghani Zeghib Introduction Motivations and questions Examples Results Results Previous results Linear Dynamics General considerations Furstenberg Lemma Lorentz Dynamics://www.umpa.ens-lyon.fr/~zeghib/ (joint work with Paolo Piccione) #12;Dynamics on Lorentz manifolds Abdelghani Zeghib Introduction

  15. Introduction Basic dynamics

    E-Print Network [OSTI]

    LaCasce, Joseph H.

    Introduction Basic dynamics The Gulf Stream The thermohaline circulation Ocean currents: some misconceptions and some dynamics Joe LaCasce Dept. Geosciences October 30, 2012 Joe LaCasce Dept. Geosciences Ocean currents: some misconceptions and some dynamics #12;Introduction Basic dynamics The Gulf Stream

  16. Tribological behavior of Ti-Al-Si-C-N hard coatings deposited by hybrid arc-enhanced magnetron sputtering

    SciTech Connect (OSTI)

    Wu Guizhi; Ma Shengli; Xu Kewei; Chu, Paul K [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China); Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong)

    2012-03-15T23:59:59.000Z

    Ti-Al-Si-C-N hard coatings are deposited on high speed steel by hybrid arc-enhanced magnetron sputtering, and the hardness, adhesion, and tribological behavior are studied. On account of the nanocomposite structure, the coatings possess hardness of more than 30 GPa. Failure of the coating during the scratch test is due to the buckling and wedge spallation failure mechanism. Compared to Ti-Al-Si-N, the presence of C in the Ti-Al-Si-C-N coatings leads to reduced friction coefficient and wear rate, indicating effective lubrication rendered by amorphous C. According to the wear tracks examined by scanning electron microscopy, the wear mechanism can be explained by plowing abrasion.

  17. Electron microscopy and small angle neutron scattering study of precipitation in low alloy steel submerged-arc welds

    SciTech Connect (OSTI)

    Williams, T.J. [Rolls-Royce and Associates Ltd., Raynesway (United Kingdom); Phythian, W.J. [AEA Reactors Services, Didcot (United Kingdom)

    1996-12-31T23:59:59.000Z

    In previous studies, submerged-arc welds with a range of compositions were irradiated in test reactors over a range of dose and dose-rates. The effect of irradiation was measured by Charpy V-notch and hardness tests, and an irradiation response model was developed. In this paper the authors report the results of a combined electron microscopy and small angle neutron scattering (SANS) study on material from some of the Charpy specimens. The results have been interpreted in terms of the Russell and Brown modulus hardening model. In general they have confirmed the predictions of the irradiation response model, and shown that the copper precipitation contribution to the observed macroscopic to the observed macroscopic hardening is strongly dependent on nickel, dose and dose-rate.

  18. Abnormal macropore formation during double-sided gas tungsten arc welding of magnesium AZ91D alloy

    SciTech Connect (OSTI)

    Shen Jun [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China)], E-mail: shenjun2626@163.com; You Guoqiang; Long Siyuan [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China); Pan Fusheng [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2008-08-15T23:59:59.000Z

    One of the major concerns during gas tungsten arc (GTA) welding of cast magnesium alloys is the presence of large macroporosity in weldments, normally thought to occur from the presence of gas in the castings. In this study, a double-sided GTA welding process was adopted to join wrought magnesium AZ91D alloy plates. Micropores were formed in the weld zone of the first side that was welded, due to precipitation of H{sub 2} as the mushy zone freezes. When the reverse side was welded, the heat generated caused the mushy zone in the initial weld to reform. The micropores in the initial weld then coalesced and expanded to form macropores by means of gas expansion through small holes that are present at the grain boundaries in the partially melted zone. Macropores in the partially melted zone increase with increased heat input, so that when a filler metal is used the macropores are smaller in number and in size.

  19. Integrating GIS with Distributed Applications Using Dynamic Data-Sharing Mechanisms

    SciTech Connect (OSTI)

    Burnett, Robert A. (BATTELLE (PACIFIC NW LAB)); Tzemos, Spyridon (BATTELLE (PACIFIC NW LAB)); Stoops, LaMar R. (BATTELLE (PACIFIC NW LAB))

    2002-08-21T23:59:59.000Z

    Effective integration of a stand-alone GIS (e.g., ArcView 3.x) into a complex distributed software application requires an efficient, reliable mechanism for passing data and function requests to and from the GIS component. This paper describes the use of dynamic data-sharing and inter-process communication mechanisms to integrate GIS capability into a multi-jurisdictional distributed emergency management information system. These mechanisms include dynamic layer updates from spatial and attribute information shared via a distributed relational database across multiple sites; storage of private and shared ViewMarks to facilitate consistent GIS views; and asynchronous inter-process communication using function queuing and a data sharing library.

  20. Tariffs with Dynamic Supply Response

    E-Print Network [OSTI]

    Karp, Larry

    1985-01-01T23:59:59.000Z

    Giannini FDN iibrary TARIFFS WITH DYNAMIC SUPPLY RESWNSEpaper studies the optimal tariff in a dynamic framework. Thesellers, the optimal tariff is dynam- ically inconsistent;

  1. Dynamics of structural priming 

    E-Print Network [OSTI]

    Malhotra, Gaurav

    2009-01-01T23:59:59.000Z

    for understanding various aspects of syntactic priming. Cognitive processes are modelled as dynamical systems that can change their behaviour when they process information. We use these dynamical systems to investigate how each episode of language comprehension...

  2. Categorical Introduction to Dynamical Systems Symbolic Dynamical Systems

    E-Print Network [OSTI]

    Kahng, Byung-Jay

    Categorical Introduction to Dynamical Systems Symbolic Dynamical Systems Symbolic Embedding Examples Results Embeddings in Symbolic Dynamical Systems Jonathan Jaquette Swarthmore College July 22, 2009 Jonathan Jaquette Embeddings in Symbolic Dynamical Systems #12;Categorical Introduction

  3. Dynamics of Carroll Particles

    E-Print Network [OSTI]

    Eric Bergshoeff; Joaquim Gomis; Giorgio Longhi

    2014-05-31T23:59:59.000Z

    We investigate particles whose dynamics is invariant under the Carroll group. Although a single free such Carroll particle has no non-trivial dynamics (`the Carroll particle does not move') we show that there exists non-trivial dynamics for a set of interacting Carroll particles. Furthermore, we gauge the Carroll algebra and couple the Carroll particle to these gauge fields. It turns out that for such a coupled system even a single Carroll particle can have non-trivial dynamics.

  4. Proposal for the Purchase, Without a Call for Tenders, of Thyristor Assemblies to be Fitted into the PS Magnet Power Supply as Replacement for the Mercury-Arc Rectifiers

    E-Print Network [OSTI]

    1977-01-01T23:59:59.000Z

    Proposal for the Purchase, Without a Call for Tenders, of Thyristor Assemblies to be Fitted into the PS Magnet Power Supply as Replacement for the Mercury-Arc Rectifiers

  5. JOURNAL DE PHYSIQUE CoZZoque C7, suppthent au n07, Tome 40, J u i Z k t 1979, page C7-267 ENHANCEDARCING AS A FUNCTIONW ORGANIC EXPOSUREAND ARC CURRENT

    E-Print Network [OSTI]

    Boyer, Edmond

    ENHANCEDARCING AS A FUNCTIONW ORGANIC EXPOSUREAND ARC CURRENT Pd AND PdIAg ELECTRODES E.W. Gray and J.R. Pharney curves is predicted by the activation theory of Gray, Uhrig and Hohnstreiter. Article published online

  6. Dynamics of Anisotropic Universes

    E-Print Network [OSTI]

    Jerome Perez

    2006-03-30T23:59:59.000Z

    We present a general study of the dynamical properties of Anisotropic Bianchi Universes in the context of Einstein General Relativity. Integrability results using Kovalevskaya exponents are reported and connected to general knowledge about Bianchi dynamics. Finally, dynamics toward singularity in Bianchi type VIII and IX universes are showed to be equivalent in some precise sence.

  7. Social Dynamics Introduction

    E-Print Network [OSTI]

    Barrett, Jeffrey A.

    Social Dynamics Introduction Part I: Correlation and the Social Contract Introduction to part I 1: University of Utah Press. 47-69. Part II: Importance of Dynamics Introduction to part II 1. Trust, Risk Significance of Some Simple Evolutionary Models (2000) Philosophy of Science 67: 94-113. 4. Dynamics

  8. Atmospheric Dynamics II Instructor

    E-Print Network [OSTI]

    AT602 Atmospheric Dynamics II 2 credits Instructor: David W. J. Thompson davet: An Introduction to Dynamic Meteorology, 5th Edition, Academic Press (recommended) · Marshall, J., and Plumb, R. A., 2008: Atmosphere, Ocean, and Climate Dynamics: An Introductory Text, Academic Press. · Vallis, G. K

  9. Intramolecular and nonlinear dynamics

    SciTech Connect (OSTI)

    Davis, M.J. [Argonne National Laboratory, IL (United States)

    1993-12-01T23:59:59.000Z

    Research in this program focuses on three interconnected areas. The first involves the study of intramolecular dynamics, particularly of highly excited systems. The second area involves the use of nonlinear dynamics as a tool for the study of molecular dynamics and complex kinetics. The third area is the study of the classical/quantum correspondence for highly excited systems, particularly systems exhibiting classical chaos.

  10. Cybersecurity Dynamics Shouhuai Xu

    E-Print Network [OSTI]

    Xu, Shouhuai

    Antonio ABSTRACT We explore the emerging field of Cybersecurity Dynamics, a candidate foundation been driving the study of security for decades -- the idea of cybersecurity dynamics emergedCybersecurity Dynamics Shouhuai Xu Department of Computer Science, University of Texas at San

  11. 17. METAPOPULATION DYNAMICS OF

    E-Print Network [OSTI]

    17. METAPOPULATION DYNAMICS OF INFECTIOUS DISEASES Matt J. Keeling, Ottar N. Bjørnstad, and Bryan T resonances for the dynamics of parasites. This is particularly true for microparasitic infections" growth of the parasite population. Thus, at the scale of the host popu- lation, infectious dynamics bears

  12. Treatment plan comparison of Linac step and shoot,Tomotherapy, RapidArc, and Proton therapy for prostate cancer using dosimetrical and biological index

    E-Print Network [OSTI]

    Lee, Suk; Chang, Kyung Hwan; Shim, Jang Bo; Kim, Kwang Hyeon; Lee, Nam Kwon; Park, Young Je; Kim, Chul Yong; Cho, Sam Ju; Lee, Sang Hoon; Min, Chul Kee; Kim, Woo Chul; Cho, Kwang Hwan; Huh, Hyun Do; Lim, Sangwook; Shin, Dongho

    2015-01-01T23:59:59.000Z

    The purpose of this study was to use various dosimetrical indices to determine the best IMRT modality technique for treating patients with prostate cancer. Ten patients with prostate cancer were included in this study. Intensity modulated radiation therapy plans were designed to include different modalities, including the linac step and shoot, Tomotherapy, RapidArc, and Proton systems. Various dosimetrical indices, like the prescription isodose to target volume (PITV) ratio, conformity index (CI), homogeneity index (HI), target coverage index (TCI), modified dose homogeneity index (MHI), conformation number (CN), critical organ scoring index (COSI), and quality factor (QF) were determined to compare the different treatment plans. Biological indices such as the generalized equivalent uniform dose (gEUD), based tumor control probability (TCP), and normal tissue complication probability (NTCP) were also calculated and used to compare the treatment plans. The RapidArc plan attained better PTV coverage, as evidenc...

  13. Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

    SciTech Connect (OSTI)

    Eaton, W.C. [ed.

    1995-05-31T23:59:59.000Z

    This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace.

  14. Slow dynamics and anomalous nonlinear fast dynamics in diverse solids

    E-Print Network [OSTI]

    Slow dynamics and anomalous nonlinear fast dynamics in diverse solids Paul Johnsona) Geophysics study of anomalous nonlinear fast dynamics and slow dynamics in a number of solids. Observations are presented from seven diverse materials showing that anomalous nonlinear fast dynamics ANFD and slow dynamics

  15. Using ArcGIS to extrapolate greenhouse gas emissions on the Pengxi River, a tributary of the Three Gorges Reservoir in China

    E-Print Network [OSTI]

    Yasarer, Lindsey

    2014-11-19T23:59:59.000Z

    Using ArcGIS to extrapolate greenhouse gas emissions on the Pengxi River, a tributary of the Three Gorges Reservoir in China Lindsey MW Yasarer, PhD Candidate, University of Kansas Dr. Zhe Li, Associate Professor, Chongqing University Dr...D Student, Chongqing University • Zhengyu Zhang and Xiao Yao, Masters Students, Chongqing University • CSTEC: China Science and Technology Exchange Center • NSF EAPSI Program The research was funded by the National Natural Science Foundation of China...

  16. High-pressure arcs as vacuum-atmosphere interface and plasma lens for nonvacuum electron beam welding machines, electron beam melting, and nonvacuum ion material modification

    SciTech Connect (OSTI)

    Hershcovitch, A. [AGS Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)] [AGS Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

    1995-11-01T23:59:59.000Z

    Atmospheric pressure plasmas can be used to provide a vacuum-atmosphere interface as an alternative to differential pumping. Vacuum-atmosphere interface utilizing a cascade arc discharge was successfully demonstrated and a 175 keV electron beam was successfully propagated from vacuum through such a plasma interface and out into atmospheric pressure. Included in the article are a theoretical framework, experimental results, and possible applications for this novel interface. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  17. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density 

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT... DENSITY A Thesis by ROBIN KENT DEVORE Approved as to style and content by: C alarm n of o itte Hea o partment e er Member December 1973 ABSTRACT The Effective Spectral Irradiance of Ultraviolet Radiations from Inert-Gas-Shielded Welding...

  18. A dosimetric comparative study: Volumetric modulated arc therapy vs intensity-modulated radiation therapy in the treatment of nasal cavity carcinomas

    SciTech Connect (OSTI)

    Nguyen, Kham, E-mail: khamdiep@gmail.com [School of Health Professions, Medical Dosimetry Program, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); UT MD Anderson Cancer Center, School of Health Professions—Unit 2, Houston, TX (United States); Cummings, David; Lanza, Vincent C.; Morris, Kathleen; Wang, Congjun; Sutton, Jordan; Garcia, John [School of Health Professions, Medical Dosimetry Program, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); UT MD Anderson Cancer Center, School of Health Professions—Unit 2, Houston, TX (United States)

    2013-10-01T23:59:59.000Z

    The purpose of this study was to evaluate the differences between volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) in the treatment of nasal cavity carcinomas. The treatment of 10 patients, who had completed IMRT treatment for resected tumors of the nasal cavity, was replanned with the Philips Pinnacle{sup 3} Version 9 treatment-planning system. The IMRT plans used a 9-beam technique whereas the VMAT (known as SmartArc) plans used a 3-arc technique. Both types of plans were optimized using Philips Pinnacle{sup 3} Direct Machine Parameter Optimization algorithm. IMRT and VMAT plans' quality was compared by evaluating the maximum, minimum, and mean doses to the target volumes and organs at risk, monitor units (MUs), and the treatment delivery time. Our results indicate that VMAT is capable of greatly reducing treatment delivery time and MUs compared with IMRT. The reduction of treatment delivery time and MUs can decrease the effects of intrafractional uncertainties that can occur because of patient movement during treatment delivery. VMAT's plans further reduce doses to critical structures that are in close proximity to the target volume.

  19. THE SLOAN BRIGHT ARCS SURVEY: DISCOVERY OF SEVEN NEW STRONGLY LENSED GALAXIES FROM z = 0.66-2.94

    SciTech Connect (OSTI)

    Kubo, Jeffrey M.; Allam, Sahar S.; Drabek, Emily; Lin, Huan; Tucker, Douglas; Buckley-Geer, Elizabeth J.; Diehl, H. Thomas; Soares-Santos, Marcelle; Hao Jiangang; Kubik, Donna; Annis, James; Frieman, Joshua A. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Wiesner, Matthew [Department of Physics, Northern Illinois University, DeKalb, IL 60115 (United States); West, Anderson [The Illinois Math and Science Academy, Aurora, IL 60506 (United States)

    2010-12-01T23:59:59.000Z

    We report the discovery of seven new, very bright gravitational lens systems from our ongoing gravitational lens search, the Sloan Bright Arcs Survey (SBAS). Two of the systems are confirmed to have high source redshifts z = 2.19 and z = 2.94. Three other systems lie at intermediate redshift with z = 1.33, 1.82, 1.93 and two systems are at low redshift z = 0.66, 0.86. The lensed source galaxies in all of these systems are bright, with i-band magnitudes ranging from 19.73 to 22.06. We present the spectrum of each of the source galaxies in these systems along with estimates of the Einstein radius for each system. The foreground lens in most systems is identified by a red sequence based cluster finder as a galaxy group; one system is identified as a moderately rich cluster. In total, SBAS has now discovered 19 strong lens systems in the SDSS imaging data, 8 of which are among the highest surface brightness z {approx_equal} 2-3 galaxies known.

  20. Adaptive Optics Imaging of IRAS 18276-1431: a bipolar pre-planetary nebula with circumstellar "searchlight beams" and "arcs"

    E-Print Network [OSTI]

    Contreras, C S; Sahai, R; De Paz, A G; Morris, M

    2006-01-01T23:59:59.000Z

    We present high-angular resolution images of the post-AGB nebula IRAS18276-1431 (also known as OH17.7-2.0) obtained with the Keck II Adaptive Optics (AO) system in its Natural Guide Star (NGS) mode in the Kp, Lp, and Ms near-infrared bands. We also present supporting optical F606W and F814W HST images as well as interferometric observations of the 12CO(J=1-0), 13CO(J=1-0), and 2.6mm continuum emission with OVRO. The envelope of IRAS18276-1431 displays a clear bipolar morphology in our optical and NIR images with two lobes separated by a dark waist and surrounded by a faint 4.5"x3.4" halo. Our Kp-band image reveals two pairs of radial ``searchlight beams'' emerging from the nebula center and several intersecting, arc-like features. From our CO data we derive a mass of M>0.38[D/3kpc]^2 Msun and an expansion velocity v_exp=17km/s for the molecular envelope. The density in the halo follows a radial power-law proportional to r^-3, which is consistent with a mass-loss rate increasing with time. Analysis of the NIR ...

  1. Aluminum Bronze Alloys to Improve the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs and Side Vents.

    SciTech Connect (OSTI)

    Lawrence C. Boyd Jr.; Dr. Vinod K. Sikka

    2006-12-29T23:59:59.000Z

    Energy Industries of Ohio was the lead organization for a consortium that examined the current situation involving the service life of electric arc and basic oxygen furnace hoods, roofs and side vents. Republic Engineered Products (REP), one of the project partners, installed a full-scale Al-Bronze “skirt” in their BOF at their Lorain OH facility, believed to be the first such installation of this alloy in this service. In 24 months of operation, the Al-Bronze skirt has processed a total of 4,563 heats, requiring only 2 shutdowns for maintenance, both related to physical damage to the skirt from operational mishaps. Yearly energy savings related to the REP facility are projected to be ~ 10 billion Btu's with significant additional environmental and productivity benefits. In recognition of the excellent results, this project was selected as the winner of the Ohio’s 2006 Governor’s Award for Excellence in Energy, the state’s award for outstanding achievements in energy efficiency.

  2. Mechanical properties and microstructures of a magnesium alloy gas tungsten arc welded with a cadmium chloride flux

    SciTech Connect (OSTI)

    Zhang, Z.D. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, L.M. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)], E-mail: liulm@dlut.edu.cn; Shen, Y.; Wang, L. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2008-01-15T23:59:59.000Z

    Gas tungsten arc (GTA) welds were prepared on 5-mm thick plates of wrought magnesium AZ31B alloy, using an activated flux. The microstructural characteristics of the weld joint were investigated using optical and scanning microscopy, and the fusion zone microstructure was compared with that of the base metal. The elemental distribution was also investigated by electron probe microanalysis (EPMA). Mechanical properties were determined by standard tensile tests on small-scale specimens. The as-welded fusion zone prepared using a CdCl{sub 2} flux exhibited a larger grain size than that prepared without flux; the microstructure consisted of matrix {alpha}-Mg, eutectic {alpha}-Mg and {beta}-Al{sub 12}Mg{sub 17}. The HAZ was observed to be slightly wider for the weld prepared with a CdCl{sub 2} flux compared to that prepared without flux; thus the tensile strength was lower for the flux-prepared weld. The fact that neither Cd nor Cl was detected in the weld seam by EPMA indicates that the CdCl{sub 2} flux has a small effect on convection in the weld pool.

  3. Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect (OSTI)

    Xu Nan [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Xie Weidong; Wang Linzhi; Wang Dan; Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2010-07-15T23:59:59.000Z

    In this study, the effects of heat input on the distribution of microhardness of tungsten inert gas (TIG) arc welded hot-extruded AZ61 magnesium alloy joints were investigated. The results show that with an increase of heat input, the distributions of microhardness at the top and bottom of the welded joints are different because they are determined by both the effect of grain coarsening and the effect of dispersion strengthening. With an increase of the heat input, the microhardness of the heat-affected zone (HAZ) at the top and bottom of welded joints and the fusion zone (FZ) at the bottom of welded joints decreased gradually, while the microhardness of the FZ at the top of welded joints decreased initially and then increased sharply. The reason for the abnormal distribution of microhardness of the FZ at the top of the welded joints is that this area is close to the heat source during welding and then large numbers of hard {beta}-Mg{sub 17}(Al,Zn){sub 12} particles are precipitated. Hence, in this case, the effect of dispersion strengthening dominated the microhardness.

  4. GTAW penetration based on electrode tip location versus weld joint center line. [Gas Tungsten Arc Welding (GTAW)

    SciTech Connect (OSTI)

    Daumeyer, G.J. III.

    1992-11-01T23:59:59.000Z

    Gas Tungsten Arc Welding (GTAW) is often the chosen process for final enclosure welds of heat sensitive electrical and electronic product. GTAW is used to produce welds that satisfy design requirements (usually a penetration requirement) and not expose the product to such high heat that would cause unwanted damage. An important variable in the GTAW process is the location of the Electrode tip over the weld joint center line. This study shows the tolerance of positional location over a narrow scope. Using coupons which represent the W88 container weld joint geometry, penetration vs. electrode tip positional location (offset) is investigated. Results indicate a positional location tolerance of [plus minus] 0.008 in. is acceptable. Several different major components (MCS) supporting various weapons programs require low heat input GTA welds. The electrode tip positional location tolerance is determined by each MC's weld joint tolerances and heat sensitivity. For this short study, the weld joint geometry of a container weld was used. These coupons were welded with the specified weld schedule and one additional weld schedule in order to show the relationship based on both travel speed and gap. Multiple coupon welds were made to eliminate error in the results. Within the scope of this research, a positional tolerance of [plus minus] 0.008 in. of the electrode center over the weld joint center is required. For other MCs this tolerance may be tighter or more relaxed depending upon the specific considerations.

  5. Analysis of effect of temperature gradients on surface-tension phenomena in gas-tungsten-arc welds

    SciTech Connect (OSTI)

    Lee, H.A.; Chien, P.S.J.

    1982-10-01T23:59:59.000Z

    Fluid motion directed by surface tension is considered as a contributor to heat penetration in a weld pool. The potential phenomena at the gas-liquid interface were analyzed, and the dependence of surface motion on temperature in the gas-tungsten-arc (GTA) welding process was examined. An existing heat-transfer model was used and was able to predict weld size to +- 50% of the actual value. A momentum-transfer equation was derived by considering the contribution of Lorentz force. The momentum boundary condition was developed and was able to predict the Marangoni effect. The magnitude of surface-tension-driven force is comparable to the gravitational force on one gram. An empirical approach was proposed to couple heat-transfer and momentum-transfer phenomena. A dimensional analysis identified the pertinent dimensionless groups as Reynolds, Weber, Froude, Peclet, and Power numbers and a dimensionless velocity. A simplified form of the correction was developed by combining dimensionless groups to yield a correlation with the Bond, Prandtl, and modified power numbers. Future experimental work was proposed to test the functionality of the dimensionless groups.

  6. Dynamical friction in modified Newtonian dynamics

    E-Print Network [OSTI]

    C. Nipoti; L. Ciotti; J. Binney; P. Londrillo

    2008-03-31T23:59:59.000Z

    We have tested a previous analytical estimate of the dynamical friction timescale in Modified Newtonian Dynamics (MOND) with fully non-linear N-body simulations. The simulations confirm that the dynamical friction timescale is significantly shorter in MOND than in equivalent Newtonian systems, i.e. systems with the same phase-space distribution of baryons and additional dark matter. An apparent conflict between this result and the long timescales determined for bars to slow and mergers to be completed in previous N-body simulations of MOND systems is explained. The confirmation of the short dynamical-friction timescale in MOND underlines the challenge that the Fornax dwarf spheroidal poses to the viability of MOND.

  7. AP report no. 9675 The dynamics of H absorption in and adsorption on Cu(111)

    E-Print Network [OSTI]

    Persson, Mats

    the energy curves are in good agreement with available experimental data. We find that the calculated en; a simple estimation shows that the energy transfer to electron­hole pairs can be as efficient as the energy¨oteborg University, S­412 96, G¨oteborg, Sweden B. Hammer Center for Atomic­Scale Materials Physics and Physics

  8. Next Generation Metallic Iron Nodule Technology in Electric Arc Steelmaking - Phase II

    SciTech Connect (OSTI)

    Donald R. Fosnacht; Iwao Iwasaki; Richard F. Kiesel; David J. Englund; David W. Hendrickson; Rodney L. Bleifuss

    2010-12-22T23:59:59.000Z

    The current trend in the steel industry is a gradual decline in conventional steelmaking from taconite pellets in blast furnaces, and an increasing number of alternative processes using metallic scrap iron, pig iron and metallized iron ore products. Currently, iron ores from Minnesota and Michigan are pelletized and shipped to the lower Great Lakes ports as blast furnace feed. The existing transportation system and infrastructure is geared to handling these bulk materials. In order to expand the opportunities for the existing iron ore mines beyond their blast furnace customer base, a new material is needed to satisfy the needs of the emerging steel industry while utilizing the existing infrastructure and materials handling. A recent commercial installation employing Kobe Steel’s ITmk3 process, was installed in Northeastern Minnesota. The basic process uses a moving hearth furnace to directly reduce iron oxides to metallic iron from a mixture of iron ore, coals and additives. The resulting products can be shipped using the existing infrastructure for use in various steelmaking processes. The technology reportedly saves energy by 30% over the current integrated steelmaking process and reduces emissions by more than 40%. A similar large-scale pilot plant campaign is also currently in progress using JFE Steel’s Hi-QIP process in Japan. The objective of this proposal is to build upon and improve the technology demonstrated by Kobe Steel and JFE, by further reducing cost, improving quality and creating added incentive for commercial development. This project expands previous research conducted at the University of Minnesota Duluth’s Natural Resources Research Institute and that reported by Kobe and JFE Steel. Three major issues have been identified and are addressed in this project for producing high-quality nodular reduced iron (NRI) at low cost: (1) reduce the processing temperature, (2) control the furnace gas atmosphere over the NRI, and (3) effectively use sub-bituminous coal as a reductant. From over 4000 laboratory tube and box furnace tests, it was established that the correct combination of additives, fluxes, and reductant while controlling the concentration of CO and CO2 in the furnace atmosphere (a) lowers the operating temperature, (b) decreases the use of reductant coal (c) generates less micro nodules of iron, and (d) promotes desulphurization. The laboratory scale work was subsequently verified on 12.2 m (40 ft) long pilot scale furnace. High quality NRI could be produced on a routine basis using the pilot furnace facility with energy provided from oxy-gas or oxy-coal burner technologies. Specific strategies were developed to allow the use of sub-bituminous coals both as a hearth material and as part of the reaction mixture. Computational Fluid Dynamics (CFD) modeling was used to study the overall carbothermic reduction and smelting process. The movement of the furnace gas on a pilot hearth furnace and larger simulated furnaces and various means of controlling the gas atmosphere were evaluated. Various atmosphere control methods were identified and tested during the course of the investigation. Based on the results, the appropriate modifications to the furnace were made and tested at the pilot scale. A series of reduction and smelting tests were conducted to verify the utility of the processing conditions. During this phase, the overall energy use characteristics, raw materials, alternative fuels, and the overall economics predicted for full scale implementation were analyzed. The results indicate that it should be possible to lower reaction temperatures while simultaneously producing low sulfur, high carbon NRI if the right mix chemistry and atmosphere are employed. Recommendations for moving the technology to the next stage of commercialization are presented.

  9. Prediction of Thermal Conductivity for Irradiated SiC/SiC Composites by Informing Continuum Models with Molecular Dynamics Data

    SciTech Connect (OSTI)

    Nguyen, Ba Nghiep; Gao, Fei; Henager, Charles H.; Kurtz, Richard J.

    2014-05-01T23:59:59.000Z

    This article proposes a new method to estimate the thermal conductivity of SiC/SiC composites subjected to neutron irradiation. The modeling method bridges different scales from the atomic scale to the scale of a 2D SiC/SiC composite. First, it studies the irradiation-induced point defects in perfect crystalline SiC using molecular dynamics (MD) simulations to compute the defect thermal resistance as a function of vacancy concentration and irradiation dose. The concept of defect thermal resistance is explored explicitly in the MD data using vacancy concentrations and thermal conductivity decrements due to phonon scattering. Point defect-induced swelling for chemical vapor deposited (CVD) SiC as a function of irradiation dose is approximated by scaling the corresponding MD results for perfect crystal ?-SiC to experimental data for CVD-SiC at various temperatures. The computed thermal defect resistance, thermal conductivity as a function of grain size, and definition of defect thermal resistance are used to compute the thermal conductivities of CVD-SiC, isothermal chemical vapor infiltrated (ICVI) SiC and nearly-stoichiometric SiC fibers. The computed fiber and ICVI-SiC matrix thermal conductivities are then used as input for an Eshelby-Mori-Tanaka approach to compute the thermal conductivities of 2D SiC/SiC composites subjected to neutron irradiation within the same irradiation doses. Predicted thermal conductivities for an irradiated Tyranno-SA/ICVI-SiC composite are found to be comparable to available experimental data for a similar composite ICVI-processed with these fibers.

  10. Shape Dynamics. An Introduction

    E-Print Network [OSTI]

    Julian Barbour

    2011-05-01T23:59:59.000Z

    Shape dynamics is a completely background-independent universal framework of dynamical theories from which all absolute elements have been eliminated. For particles, only the variables that describe the shapes of the instantaneous particle configurations are dynamical. In the case of Riemannian three-geometries, the only dynamical variables are the parts of the metric that determine angles. The local scale factor plays no role. This leads to a shape-dynamic theory of gravity in which the four-dimensional diffeomorphism invariance of general relativity is replaced by three-dimensional diffeomorphism invariance and three-dimensional conformal invariance. Despite this difference of symmetry groups, it is remarkable that the predictions of the two theories -- shape dynamics and general relativity -- agree on spacetime foliations by hypersurfaces of constant mean extrinsic curvature. However, the two theories are distinct, with shape dynamics having a much more restrictive set of solutions. There are indications that the symmetry group of shape dynamics makes it more amenable to quantization and thus to the creation of quantum gravity. This introduction presents in simple terms the arguments for shape dynamics, its implementation techniques, and a survey of existing results.

  11. Dynamic Instruction Fusion

    E-Print Network [OSTI]

    Lee, Ian

    2012-01-01T23:59:59.000Z

    SANTA CRUZ DYNAMIC INSTRUCTION FUSION A thesis submitted in4 2.2 Instruction Fusion & Complex10 3.1 Fusion Selection

  12. Nanoindentation Under Dynamic Conditions

    E-Print Network [OSTI]

    Wheeler, Jeffrey M

    2009-05-22T23:59:59.000Z

    ............................................................................................ 98  6.3.1  Data Analysis ........................................................................................... 99  6.3.2  Dynamic Compliance ............................................................................. 103  6.3.3  Strain Rates...

  13. On-line weld penetration detection and control in automated gas tungsten arc welding. Ph.D. Thesis

    SciTech Connect (OSTI)

    Banerjee, P.

    1994-01-01T23:59:59.000Z

    The present work was undertaken to study the feasibility of monitoring and controlling weld penetration variations in real-time using an infrared detector. Weld penetration variations induced on mild steel plates were examined with an infrared detector and the acquired data analyzed to detect weld penetration variations using a mathematical analysis. Selected weld penetration indicators were developed and used to demonstrate on-line weld penetration control. A three-dimensional solid-state, transient heat transfer model was also developed to help identify key changes in thermal distributions which could be used as weld penetration indicators. A transient three-dimensional heat transfer model was used to solve the differential energy balance for the GTA welding process. The computed temperatures obtained from the model were used to determine the variation of the isothermal map, surface temperature profile and temperature gradient with weld penetration. Good agreement between experimental and computed indicators was obtained. Gas tungsten arc welds were performed on steel plates with intentionally introduced defects such as sudden thickness changes and minor element content changes. Extensive mathematical analysis helped correlate weld penetration variations to parameters such as the peak infrared intensity, intensity gradient over a fixed distance, intensity gradient at the inflection points in the first differential of the intensity profile (linescan), computed width of the weld pool, intensity gradient at a point in the weld pool, area enclosed by the linescan and area enclosed by the linescan after compensating for background illumination. The shape of the weld pool front was also determined from a differential analysis of the infrared data. Inconsistent behavior of some weld penetration indicators led to their elimination from the selection process for the best error signal.

  14. Dynamic strength of concrete

    SciTech Connect (OSTI)

    Logunova, V.A.; Rudenko, V.V.; Radionov, A.K.; Sokolov, I.B.

    1994-12-01T23:59:59.000Z

    Recommendations for evaluating the dynamic strength of concrete structures at hydroelectric power stations are given. Both existing and planned structures are addressed. Equations are provided for determing the design compressive and tensile strength of concrete. A formula is provided for determining design dynamic strength of concrete of various ages under uniform compression. 3 refs., 1 fig., 2 tabs.

  15. Quantitative Chemical Imaging of Atomic-Scale Chemistry Changes at Interfaces Research Team: Nigel Browning, Hao Yang

    E-Print Network [OSTI]

    to increase throughput for materials analysis; focus on variance and similarities between materials systems Successes 10 invited presentations at conferences and research institutions, 3 papers published Project 2 symmetry across a variety of materials systems. Generic Grain Boundary Structures 0.5 nm 0.5 nm 22.6° 13

  16. Effect of atomic scale plasticity on hydrogen diffusion in iron: Quantum mechanically informed and on-the-fly kinetic

    E-Print Network [OSTI]

    Ortiz, Michael

    across several disciplines such as surface chemistry and catalysis, applied physics, metallurgy and on-the-fly kinetic Monte Carlo simulations A. Ramasubramaniam Program in Applied and Computational) Department of Mechanical and Aerospace Engineering and Program in Applied and Computational Mathematics

  17. Understanding Metal Oxide Surfaces at the Atomic Scale: STM Investigations of Bulk-defect Dependent Surface Processes

    E-Print Network [OSTI]

    Diebold, Ulrike

    , photocatalysis, solar panels, gas sensors, as protective or optical coatings, in biocompatible materials, in Li surface structures with many undercoordinated atoms. The desorption behavior of elemental S, dosed at room

  18. Atomic-scale investigation of point defects and hydrogen-solute atmospheres on the edge dislocation mobility in alpha iron

    SciTech Connect (OSTI)

    Bhatia, M. A.; Solanki, K. N., E-mail: kiran.solanki@asu.edu [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Groh, S. [Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg 09556 (Germany)

    2014-08-14T23:59:59.000Z

    In this study, we present atomistic mechanisms of 1/2 [111](11{sup ¯}0) edge dislocation interactions with point defects (hydrogen and vacancies) and hydrogen solute atmospheres in body centered cubic (bcc) iron. In metals such as iron, increases in hydrogen concentration can increase dislocation mobility and/or cleavage-type decohesion. Here, we first investigate the dislocation mobility in the presence of various point defects, i.e., change in the frictional stress as the edge dislocation interacts with (a) vacancy, (b) substitutional hydrogen, (c) one substitutional and one interstitial hydrogen, (d) interstitial hydrogen, (e) vacancy and interstitial hydrogen, and (f) two interstitial hydrogen. Second, we examine the role of a hydrogen-solute atmosphere on the rate of local dislocation velocity. The edge dislocation simulation with a vacancy in the compression side of the dislocation and an interstitial hydrogen atom at the tension side exhibit the strongest mechanical response, suggesting a higher potential barrier and hence, the higher frictional stress (i.e., ?83% higher than the pure iron Peierls stress). In the case of a dislocation interacting with a vacancy on the compressive side, the vacancy binds with the edge dislocation, resulting in an increase in the friction stress of about 28% when compared with the Peierls stress of an edge dislocation in pure iron. Furthermore, as the applied strain increases, the vacancy migrates through a dislocation transportation mechanism by attaining a velocity of the same order as the dislocation velocity. For the case of the edge dislocation interacting with interstitial hydrogen on the tension side, the hydrogen atom jumps through one layer perpendicular to the glide plane during the pinning-unpinning process. Finally, our simulation of dislocation interactions with hydrogen show first an increase in the local dislocation velocity followed by a pinning of the dislocation core in the atmosphere, resulting in resistance to dislocation motion as the dislocation moves though the hydrogen-solute atmospheres. With this systematic, atomistic study of the edge dislocation with various point defects, we show significant increase in obstacle strengths in addition to an increase in the local dislocation velocity during interaction with solute atmospheres. The results have implications for constitutive development and modeling of the hydrogen effect on dislocation mobility and deformation in metals.

  19. Relational Dynamic Bayesian Networks

    E-Print Network [OSTI]

    Domingos, P; Weld, D; 10.1613/jair.1625

    2011-01-01T23:59:59.000Z

    Stochastic processes that involve the creation of objects and relations over time are widespread, but relatively poorly studied. For example, accurate fault diagnosis in factory assembly processes requires inferring the probabilities of erroneous assembly operations, but doing this efficiently and accurately is difficult. Modeled as dynamic Bayesian networks, these processes have discrete variables with very large domains and extremely high dimensionality. In this paper, we introduce relational dynamic Bayesian networks (RDBNs), which are an extension of dynamic Bayesian networks (DBNs) to first-order logic. RDBNs are a generalization of dynamic probabilistic relational models (DPRMs), which we had proposed in our previous work to model dynamic uncertain domains. We first extend the Rao-Blackwellised particle filtering described in our earlier work to RDBNs. Next, we lift the assumptions associated with Rao-Blackwellization in RDBNs and propose two new forms of particle filtering. The first one uses abstracti...

  20. Radiological and Clinical Pneumonitis After Stereotactic Lung Radiotherapy: A Matched Analysis of Three-Dimensional Conformal and Volumetric-modulated Arc Therapy Techniques

    SciTech Connect (OSTI)

    Palma, David A., E-mail: d.palma@vumc.n [Department of Radiation Oncology, VU Medical Center, Amsterdam (Netherlands); Senan, Suresh; Haasbeek, Cornelis J.A.; Verbakel, Wilko F.A.R. [Department of Radiation Oncology, VU Medical Center, Amsterdam (Netherlands); Vincent, Andrew [Department of Biometrics, Netherlands Cancer Institute, Amsterdam (Netherlands); Lagerwaard, Frank [Department of Radiation Oncology, VU Medical Center, Amsterdam (Netherlands)

    2011-06-01T23:59:59.000Z

    Purpose: Lung fibrosis is common after stereotactic body radiotherapy (SBRT) for lung tumors, but the influence of treatment technique on rates of clinical and radiological pneumonitis is not well described. After implementing volumetric modulated arc therapy (RapidArc [RA]; Varian Medical Systems, Palo Alto, CA) for SBRT, we scored the early pulmonary changes seen with arc and conventional three-dimensional SBRT (3D-CRT). Methods and Materials: Twenty-five SBRT patients treated with RA were matched 1:2 with 50 SBRT patients treated with 3D-CRT. Dose fractionations were based on a risk-adapted strategy. Clinical pneumonitis was scored using Common Terminology Criteria for Adverse Events version 3.0. Acute radiological changes 3 months posttreatment were scored by three blinded observers. Relationships among treatment type, baseline factors, and outcomes were assessed using Spearman's correlation, Cochran-Mantel-Haenszel tests, and logistic regression. Results: The RA and 3D-CRT groups were well matched. Forty-three patients (57%) had radiological pneumonitis 3 months after treatment. Twenty-eight patients (37%) had computed tomography (CT) findings of patchy or diffuse consolidation, and 15 patients (20%) had ground-glass opacities only. Clinical pneumonitis was uncommon, and no differences were seen between 3D-CRT vs. RA patients in rates of grade 2/3 clinical pneumonitis (6% vs. 4%, respectively; p = 0.99), moderate/severe radiological changes (24% vs. 36%, respectively, p = 0.28), or patterns of CT changes (p = 0.47). Radiological severity scores were associated with larger planning target volumes (p = 0.09) and extended fractionation (p = 0.03). Conclusions: Radiological changes after lung SBRT are common with both approaches, but no differences in early clinical or radiological findings were observed after RA. Longer follow-up will be required to exclude late changes.